As we found in Part 1, conventional hydrogen production from natural gas using steam methane reforming (SMR) coupled with carbon capture and storage (CCS) is easily written off as a waste of everyone’s time and money. It’s fooling nobody. Because nearly half the CO2 emissions come from combustion in the tube furnace and other combustion equipment, there’s no more benefit to going after high CO2 captures off this equipment than from fossil gas power plant flues or the like. We’d need something new such as SMR run with renewable electric heating to give SMR a shot at survival into a decarbonized future.
Undaunted, hydrogen-as-a-fuel advocates reach for another technology: autothermal reforming (ATR). ATR isn’t something new or unknown: it is a process used at very large scale today when high carbon monoxide (CO) to hydrogen syngas mixtures are required for processes like Fischer Tropsch or methanol synthesis.
Autothermal reforming works the same way, in thermodynamics terms, that SMR works: you heat up a mixture of methane and steam to high temperatures and pass it over a catalyst, so that endothermic reactions can transform it into a mixture of CO and H2. But whereas SMRs combust fuel and transfer the heat through catalyst tubes in a tube furnace to the syngas mixture inside them, in an ATR pure oxygen is fed with the steam and methane feed in a special burner or partial oxidation catalyst inside a refractory lined pressure vessel. The heat is produced by in situ partial combustion, and the feed stream is massively overheated before being passed over the catalyst rather than supplying heat as the reactions proceed. The result is that some of the product hydrogen and CO are also combusted and hence wasted, but all the combustion products (CO2 and water) are contained in the syngas product and hence are easier to capture and remove. The downstream steps: heat recovery, water/gas shift reactor(s) and gas purification are otherwise identical to the SMR, with the exception that there’s now no fuel-hungry tube furnace to dump the gas purification system’s waste hydrogen into.
The process is, as already mentioned, less efficient than SMR if the target is pure hydrogen. Actual “efficiency” figures given are usually polluted with values being given to “export steam” that make comparisons challenging, but that ATR is less energy efficient at making H2 than SMR, assuming CO2 can be disposed of the good old way, to the atmosphere, is not in doubt. The process is currently optimized for the production of higher CO/H2 ratio syngas mixtures which are then blended with SMR output to produce the desired ratio for F-T, methanol or other syngas uses, because ATR can do that and SMR can’t without a risk of soot generation and other problems. Air-blown ATR is also used in a multi step reformer package to make H2/N2 mixtures as a feed for the Haber Bosch ammonia process.
Of course ATR is reached for by blue hydrogen advocates as soon as somebody realizes that the best possible capture from SMR, without major changes, is going to be about 50%- even ignoring methane emissions, due to SMR’s horrible burner box. So: how “blue” can we make an ATR?
If you a) take a few hits from the #hopium pipe, b) ignore methane emissions and c) restrain the project to using only renewable/nonemitting energy sources to run the CCS equipment, the answer is “as blue as you can afford!”.
In purely technical terms, there is no problem at all to remove 99.999% of the CO2 from the resulting hydrogen stream. If that were NOT possible, the product hydrogen would never meet fuelcell specifications which require the total of CO + CO2 to be below 10 ppm to avoid killing the fuelcell’s catalysts. Of course “removal” is just the first and easiest of the steps- you next need to capture, purify and store the CO2 away permanently.
Recall that the Shell Quest project targeted an 80% capture of the CO2 in the syngas mixture from the SMR, which it achieves, except when it doesn’t. That’s a fairly easy capture target from a stream with a high partial pressure of CO2 at a modest absolute pressure, and of course it’s only 80% of about 1/2 the CO2 emitted by the SMR. But as you increase the fraction of the CO2 you want to capture, two things increase: 1) energy use and 2) hydrogen wasting. The former is true in any capture process, arising from an increasingly fraught battle against entropy. While the thermodynamics and energetics are complex and vary greatly from flowsheet to flowsheet, to a first approximation, the energy to remove each order of magnitude of mass is about equal, i.e. 99% capture costs twice as much energy as 90%- for capture, not for capture and storage.
The hydrogen mass loss is likely the more challenging problem, and not just because of the need to throw away valuable product. Removing hydrogen from the captured CO2 would require yet more equipment, energy and flowsheet complexity. Unlike in the “good old days”, when hydrogen was treated as something you could vent without consequence, we now know that hydrogen itself is a GHG with GWP between 11 and 60x that of CO2. And whatever CO2 you don’t capture in your sequestration train, is going to come out in a swamp of H2 and other gases in the gas purification pressure swing absorption (PSA) unit. Without combustion equipment to easily use this material, and with the option to recompress and feed this stuff into the ATR feed being unpleasant for a number of reasons, it is likely that one would be tempted to just burn and vent the flue gas in some unabated combustion unit somewhere. That of course means you will have unabated CO2 emissions coming from that combustion stack.
The real killer to this idea however is those pesky initial assumptions we made when we were high on #hopium.
We might, because of foolish or ignorant regulation, be permitted to just ignore or discount the methane emissions, as is clearly the case with the Shell Quest project which doesn’t even mention them in its public reporting. Remember that methane emissions take Quest’s net CO2 capture from 35% to a real CO2e capture around 21%- from poor to positively craptastic. But the atmosphere won’t give us the luxury of accepting the design philosophy of Mediocrates, whose response to criticism is, “Meh- good enough!” Global warming potential (GWP) is GWP, whether it’s from CO2 or methane emissions. You can’t just pretend that methane doesn’t matter!
If you remember from Part 1, methane leakage at world average leakage rates of 1.5% add about 4 kg of CO2e for every kg of H2 produced, i.e. Methane leakage adds about 40% to the ~ 10 kg of actual CO2 released from an unabated SMR per kg it produces. So if you’re looking for CO2e capture (the total of CO2, methane, N2O and other GHGs from the process) to be very good, you basically would be forced to use the very best, lowest leakage fossil gas sources on earth, i.e. Norwegian gas, the gold standard as far as leakage goes, with leakage below 0.05%. My suggestion would be to forget about any blue hydrogen production from LNG, irrespective of its source- you need access to excellent gas via pipeline, because the leakage/venting from the extra steps to liquefy, transport and revapourize LNG will take you over the top.
Remember also that you need green electricity, and lots of it, to provide the capture and sequestration energy. ATR will generate the needed surplus heat as a result of its reduced efficiency relative to SMR, but you’ll need lots of green electricity- backed up with storage- to be able to run your ATR continuously (the only way hot units like this can run). You’ll need it to run the air separation plant, and the capture equipment, and the storage and CO2 transport compressors. Of course if you were a moron, you’d run this equipment off your product hydrogen, and watch your economics swirl down the toilet.
Finally, we can’t forget about carbon sequestration, i.e. storage. Remember that Shell Quest has an ideal storage reservoir only 60 km away from the plant, 2 km below ground. Because of the economics of CO2 sequestration, we’ll need to be nearby to a sequestration reservoir with capacity enough to take the effluent from our plant from its entire 30+ yrs of design life. And NO, we can’t accept enhanced oil recovery use for this CO2, because if we do, the atmosphere gets not only the CO2 released when that oil is burned, it gets about 40% of it back again when the oil comes to the surface. EOR is not CCS!
So: to make ATR capable of making truly blue hydrogen, any project has to line up just exactly right. It must have:
1) pipeline access to ultralow leakage fossil gas of adequate capacity
2) pipeline access to a nearby disposal reservoir of adequate capacity (forget about liquefying and shipping the CO2, that’s just going to break the bank and blow the CO2 emissions budget by time you’re done)
3) access to high capacity renewable electricity, backed up with storage to permit continuous operation (begging the question- why not just make green hydrogen!?!?!)
When I ran the numbers assuming 95% CO2 capture, 0.05% methane leakage, a world class ATR efficiency, and renewable electricity running the entire carbon capture and storage infrastructure, I was able to get the emissions down to about 1.2 kg of CO2e per kg of hydrogen produced- only about 20% more CO2e emissive than green hydrogen made by electrolysis using renewable electricity can already achieve today.
As to the cost of doing this, let’s just set that aside and dream the dream for a moment!
Hmm, are we seeing any ideal locations on earth yet? Which meet all these criteria, to make truly blue hydrogen?
Me neither.
Are we seeing enough of them to pump up the deflated dream of wasting hydrogen as a natural gas replacement fuel?
Nope.
I am however seeing lots of places which meet a couple of those criteria, who are hoping that nobody notices that the resulting hydrogen is still very blackish blue and bruise coloured, and hoping that a credulous government somewhere will turn a blind eye and write a blank cheque.
As to the notion of this kind of project being “transitional” while we wait for green hydrogen to get cheaper, please remember that this is nothing like bolting a CCS unit onto an existing SMR plant already feeding black hydrogen to a refinery or upgrader somewhere. We’re talking about bespoke new equipment, at scale so it’s cheap enough per kg, with a design life of at least 30 yrs. Equipment that doesn’t make economical hydrogen relative to today’s standard, but which is being done this way simply because it allows the energy of fossil gas to be made into fossil hydrogen with CO2e emissions that some government regulator somewhere finds tolerable. There’s no way anybody is going to build this stuff unless they’re guaranteed to be able to run it for at least those 30 yrs, unless somebody else is paying all the capital.
Finally, a reminder that even black hydrogen is not a cheap fuel. The ten year average for wholesale Henry Hub gas in the US gulf coast has been around $3.50/MMBTU over the past 10 yrs or so. Such gas can be made into saleable wholesale black hydrogen for about $1.50/kg- the aspirational target price for green hydrogen in, say, 2040 if you’ve had a few hits from the #hopium pipe, and 2050 or beyond (or never) if you’re skeptical like me. That hydrogen already costs $11/MMBTU. While I know full well that North Americans have access to incredibly cheap gas, and by world standards $11/MMBTU doesn’t sound like a very high price, I remind you that this is a wholesale cost and includes zero cost for storage or distribution. Those costs are going to be high, are going to be higher than for fossil gas for reasons of basic physics, and will be much higher than many imagine because the existing fossil gas infrastructure cannot be re-used for its distribution.
Personally I think that blue hydrogen should be taken off the barbeque because it’s been charred on all sides.
It’s done.
And while some governments are waking up to the same conclusion, as a result of the efforts of the @Hydrogen Science Coalition and numerous other groups, we can’t forget that blue hydrogen is of existential importance to the fossil fuel industry. Blue hydrogen is their “get out of jail” card in the energy Monopoly game. Even as a mere idea, rather than an actual technology, blue hydrogen allows fossil gas producers and distributors to pretend that they have a future in the energy supply market post decarbonization. They will not give up on this idea easily, and economics will drive them to put makeup over the bruises rather than making hydrogen truly blue, because the latter is very geographically limited and will also be very costly. It’s my hope that you won’t be fooled.
Disclaimer: everything you’ve just read was written by an ordinary human being, fallible and capable of error in the most mundane ways. If you find something that I’ve done wrong, and can provide references or calculations which demonstrate where I’ve gone wrong, I’ll be grateful and happy to correct my work.
If what I’ve written makes you angry merely because it puts your future ride on the fossil fuelled gravy train in doubt, then be sure to take it up with Spitfire Research.
My readers will know that I have never liked the “colours of hydrogen” that has been spread, as a meme, by the hydrogen-as-a-fuel lobby.
There is only really one kind of hydrogen in the world right now.
Hydrogen- 98.7% of it by generous estimate- is made from fossils, without meaningful carbon capture. It is barest minimum 30% blacker, per joule, in CO2 and methane emissions, than the source fuel it was made from. 30% is a best case figure, corresponding to about 10 kg of fossil CO2 emitted per kg of hydrogen you produce, corresponding to a 70% lower heating value (LHV) efficiency of converting natural gas LHV to hydrogen LHV. Start with lignite (brown coal) and it can be much worse- 30 kg CO2 per kg H2.
By definition, that’s not brown, or gray. That’s black. In fact, it’s ultra-black. It’s black-hole black.
We make up for that by not wasting hydrogen as a fuel, of course. Very little hydrogen is wasted as a fuel today. It is made, and used, as a chemical- sometimes to desulphurize or deoxygenate other fuels, and sometimes as a component in making molecules like methanol which are sometimes used as or to make fuels (i.e. Biodiesel).
I love memes- they can be an extremely effective communication tool, and as my friend Alex Grant says, “money follows memes”- people invest in mematic ideas, sometimes for good, sometimes carelessly, and often using taxpayer money.
When people use memes, especially when they use them carelessly or illegitimately, it’s fun to riff on them, as I’ve done with my headline. Sometimes it is a very useful way to get the opposing point of view across.
The hydrogen-as-a-fuel lobby have a pretty colour euphemism for another way to make hydrogen. If you make it from a fossil energy resource, but capture (some of) the CO2 released and dispose of it in some durable way, they call that “blue” hydrogen. And remember what “blue” hydrogen is, after all: it’s the last grand scam of the fossil fuel industry. It’s the only way the fossil fuel industry can pretend to have a future in the energy system post-decarbonization, aside from as a materials and chemicals supplier (about 15-25% of their current business value). Not a happy prospect, if you’re in that business, seeing your revenue shrink by 75-85%! So, any port in a storm as they say, and “blue hydrogen” to the rescue! Since carbon capture at every point source user of fossil fuels- or even at a multitude of the larger ones- is an economic and practical absurdity, the simpleminded idea is as follows:
convert natural gas to hydrogen centrally
capture the CO2, disposing of it (hopefully by enhanced oil recovery so we get paid twice)
sell hydrogen as a fuel
party like it’s 1989, before we really thought AGW was worth bothering with really
Truly rare for an academic paper, this one had the heads of certain “hydrogen is fossil fuel’s great salvation” advocates, spinning like that of the child in the Exorcist…
(warning: language and religion are both scary…)
But I’m asking a more finessed version of the same question: how blue is blue hydrogen? How blue can it really ever be? And the way I’m going to do that is a little different than what Bob and Mark did in their paper. I’m going to look at a “real”-ish “blue hydrogen” project. Not a pilot project- one done at considerable scale, which buries 1 million tonnes per year of CO2 and doesn’t try to pretend that using CO2 for enhanced oil recovery is real carbon storage, either- that’s the #1 play in the fossil fuel playbook where CCS is concerned.
And there is one to look at, but only one in the whole world. Here it is:
Quest, originally built by Shell, largely (or perhaps entirely) using money from the Canadian Federal and Alberta provincial governments, is a carbon capture and storage project on the Scotford Upgrader. Hydrogen, made by the conventional method by which most hydrogen is made in the world today (steam methane reforming (SMR)), is used to desulphurize and partially upgrade bitumen (aka “tar sands” heavy oil), for sale into the (largely USA) fossil transport fuels market. That’s a use we hope sincerely won’t be needed soon, because we need to stop burning fossils as fuels in a decarbonized future.
The great thing about Quest is that because it was largely (nearly completely) publicly funded, its data is available as a precondition of public money being spent on the project. So all you non-Canadians, please feel free to send cheques to us for all the learnings we funded on your behalf…I’ll be setting up the GoFundMe page shortly! (grin!)
Let’s look at a simplified flowsheet of a SMR so we can understand what Quest does, and doesn’t do.
The Steam Methane Reformer, Redux -(C) Spitfire Research Inc. 2021
A steam methane reformer takes natural gas (mostly methane), purifies it, mixes it with steam, preheats it, then sends it to a number of reformer tubes in parallel, suspended in a tube furnace. Each tube is filled with solid catalyst and is heated on the outside using flue gas produced by burning a mixture of fuel gas, heating the tubes to a very high temperature (well above 800 C). The reforming catalyst allows methane to react with water to form a synthesis gas mixture consisting of carbon monoxide, carbon dioxide, unreacted water vapour, a little unreacted methane, and hydrogen. The overall reactions are endothermic, i.e. requiring heat input, and that heat is supplied by the burning of fuel gas outside the tubes. That means ultimately we have to feed at least 30% of the energy we get out of the product hydrogen, into the tube furnace to supply it with heat to drive those reactions.
CH4 + H2O + heat <==> CO + CO2 + H2 with proportions depending on conditions
(image credit: Air Science Technologies Inc.)
If we want syngas, we’re done- we can separate out the water and maybe the CO2 and feed the gas on to do something useful such as making methanol or reducing iron ore to iron metal (called direct iron reduction or DRI). But we want hydrogen, so the next thing we do is cool down the hot gas in a heat recovery steam generator (HRSG) which produces the steam we need to feed the process plus perhaps a little excess. We then feed the cooled syngas mixture to one or more water-gas shift reactors. These perform the magical water-gas shift (WGS) reaction:
CO + H2O <==> CO2 + H2 + heat
…which, because it produces heat, generates more H2 the colder we run the reaction. Sometimes two steps of WGS with heat removal between them, is done. We’re now left with a stream which consists of H2, CO2, some water vapour, a little unreacted CO, and some unreacted methane, all under some pressure (about 30 bar or so).
Since we want H2, we need to remove the CO2. And here, Shell Quest becomes relevant.
In a normal SMR, the captured CO2 is usually just vented to the atmosphere because that’s the very cheapest thing we can do with it. And let’s face it, CO2 is not a commercial product, it’s a low Gibbs free energy waste molecule, valuable as a product of energy-producing reactions like combustion principally because, until recently, it was easy and cheap to dump it to the atmosphere.
Instead, Quest captures the CO2 using conventional amine absorber/stripper technology (something routinely used in chemical engineering, done at giant scale even before AGW was a “thing”). It generates a nearly pure CO2 stream which it then compresses, dries and dumps into a pipeline for disposal in a nearly perfect disposal reservoir, 2 km underground, some 60 km away from the plant. The absorber takes some pumping energy, and the stripping step takes some heat, at a reasonably high temperature, and CO2 compression takes (considerable) electricity, so we have to find that energy somewhere. We might get some from waste heat from the SMR by heat recovery, but that heat could generally be used elsewhere in the upgrader so it’s not really “free”.
…but even then, we’re not done. We still have CO, some CO2, and some unreacted methane to contend with. Generally, a pressure swing adsorption (PSA) system is used to capture and remove these contaminants. The PSA adsorbs the contaminants at pressure onto a solid adsorbent, which is then periodically depressurized to vent off a gas mixture which is, sadly, mostly hydrogen contaminated with these left-over materials. No matter, as we have a huge, hungry firebox ready to soak up all that otherwise wasted energy- the PSA’s tail gas is sent back to the tube furnace for combustion, and all the CO and CO2 leaves the flue as CO2.
Shell Quest captures about 80% of the CO2 in the syngas stream. That results in about 45% capture of the CO2 from hydrogen production at the plant, per the government website. That also means that only about 56% of the CO2 emitted by hydrogen production in the Quest SMRs is available for capture in the syngas. The other 44% comes mostly out that tube furnace flue, at atmospheric pressure, in a giant swamp of nitrogen and water vapour (some of it also comes out of a natural gas power plant somewhere). The low partial pressure (total pressure times % CO2 in the stream) means there’s a higher entropic hill to climb to capture that CO2, and that costs us energy; such a high hill in fact that it is no easier to capture the CO2 from the tube furnace flue than it would be to just skip hydrogen-as-a-fuel entirely, burn ALL the methane in, say, a gas turbine power plant, and capture the CO2 from its flue. So Quest, wisely, doesn’t even try. It makes itself quite satisfied with capturing 80% of 56%, i.e. 45% of the CO2. The easy 45%. And it does this pretty consistently, except when it doesn’t. Then, it just vents the CO2, like every other SMR on earth.
Source: Government of Alberta website, Shell Quest capture figures, 2019
(note: this 80% of the CO2 in the syngas is only 45% of the CO2 produced by the SMR unit)
Quest has been in operation for over six years, since we generous Canadians built it. And in each of those years, it has captured about 1 million tonnes of CO2 and buried it deep down from whence it will hopefully never return.
Of course Shell, on its various websites, crows about how wonderful this all is- how it’s equivalent to the emissions of about 1.25 million cars each year etc. etc. Why shouldn’t they crow? They’re not paying for it- we Canadian taxpayers are!
Cost and Schedule
How much does all this cost? And how long did it take?
Engineering started in 2009, and the CCS system was operational in 2015. Not quick…but it worked, so I guess Fluor did a good job!
The financial figures are a bit muddier. While the public money dumped into the project is very clear- $120 million from Canada and $745 million from Alberta (all Canadian dollars), the NRCan website talks about “total project costs” of $1.31 billion. The operating costs are on the order of $50 million per year, and the project life is 20 yrs, so the $1.31 billion figure isn’t the “total project cost” including operation and maintenance. The actual total capital cost is actually quite unclear. Shell itself provides no other figures that I can find easily.
But frankly it doesn’t matter that much to me. What’s half a billion between friends? Here’s why: let’s assume it cost “only” the public $845 million and neither Shell nor anybody else put a cent into it. Let’s assume, for fun, that capital is “free”, so we don’t have to argue about discounting rates. And let’s assume a steady $50 million a year, and the 20 yr operating life. Let’s ignore inflation, like we all did until recently… Roll that together at an average of 1 million tonnes per year of CO2 captured and buried, and we get ~ $92/tonne of CO2. Sounds great, right? Canada’s carbon tax is heading to $170/tonne by 2030- very soon the project will be self-funding! Shell further crows on its 5th anniversary of Quest website, that capital costs would drop by 30% next time.
Sadly, we’ve forgotten or ignored a few things. Isn’t that how my papers usually go? It looks so simple, until we get into the nasty details?!
Here’s a better, more accurate version of that first slide I showed you- it represents what’s really going on in an SMR with or without carbon capture.
Methane Leakage
For every kg of H2 we get out of Quest, by my estimates (based on a Shell presentation whose slides I do not have permission to share with you), we need to feed about 47.5 kWh of methane LHV to the SMR itself. That would, at world average methane leakage rates of 1.5%, result in about 0.055 kg of methane being leaked for every kg of H2 being produced at Quest. Before abatement, Quest generates about 9.7 kg of CO2 per kg of H2 produced, round numbers. Add 0.055 kg of methane at the 20 yr, 84x global warming potential of methane per the IPCC, we’re looking at unabated emissions of 9.7 (direct) plus 4.5 (methane) = 14.2 kg of CO2e per kg of H2, before we do any CCS. Ignoring the methane leakage makes the CO2e emissions look much nicer, doesn’t it?!
Of course if you’re a fossil fuel apologist, you’ll use the 30x CO2 GWP figure for methane from IPCC instead, and knock that 4.5 extra kg of CO2e/kg H2 down to 1.7 kg- only about 18% of the gross CO2 emissions, so not that bad. But remember- we’re considering H2 production from fossils with CCS to be a transitional strategy, because we all know it’s second (or third, or fifth…) best relative to GREEN hydrogen made by electrolysis of water using pure renewable electricity. You can, as some Exorcist head-spinners have done, write off Howarth and Jacobson’s paper (and my analysis) as mere hyperbole because we take the hydrogen-as-a-fuel lobby at its word about “blue” hydrogen being a stop-gap measure. Frankly, anybody using the 100 yr GWP for methane needs a smack upside the head- forgive me, that’s just me being ornery because I’m writing about this, rather than relaxing with a glass of bourbon watching Netflix.
…the CCS system on Quest takes 0.65 MJ of electricity and 2.1 MJ of heat per kg of CO2 captured. Most of the electricity (0.55 of 0.65) is used to run the compressors. The plant also consumes 10 T/month of amine and 1 T/month of triethylene glycol used for dehydration. Forgetting about the reagents and focusing only on the energy inputs, we discover how much it takes to capture 80% of the CO2 in the syngas, which remember is only 45% of the CO2 emitted by the SMR. Taking the (unabated, post combustion) CO2 emissions of that energy into account, but again forgetting about the methane leakage, the net capture of CO2 by Quest drops from 45%, to 35%. Just capturing the easy 45% of emissions, requires 10/35 = about 1/3 more CO2 to be emitted, in a form which is post combustion and hence uneconomical to capture.
“Blue” H2 by SMR, not quite so “redux”- (C) 2021, Spitfire Research
Witnesseth that CCS, even from a high partial pressure stream, takes sh*tloads of energy. Imagine the illegitimi, talking about doing this from 416 ppm CO2 in the atmosphere with direct air capture…
Add in the methane emissions associated with that CCS energy- another 0.44 kg CO2e (20 yr basis) on top of the 0.96 kg (direct) CO2 emissions unabated to run CCS, and Quest’s capture drops to about 21% in net CO2e terms.
$0.85 to $1.3 billion, plus $50 million per year, to capture 21% of net CO2e emissions from hydrogen production.
I’m calling that rather blackish-blue, bruise coloured hydrogen at very best. Because that’s what Quest really produces.
It’s also no model, whatsoever, for the use of fossil hydrogen, especially as a fuel, in a decarbonized future.
What Else Could We Do?
Aside from the obvious, i.e. make green hydrogen from renewable electricity and water, to replace all that black hydrogen we’ll need post-decarbonization?
You may have read previously that my former client Monolith Materials is doing an exciting project in Nebraska and has received a tentative offer of $1 billion USD in loans from USDOE to expand the project to full commercial scale. The project takes natural gas, or perhaps biogas methane (future plans), and converts it using electricity from a disused nuclear power plant (with future wind/solar plans) to pyrolyze it into carbon black and hydrogen. Carbon black is a valuable product itself, made normally from heavy oil by a filthy, emissive partial combustion process. They are making the hydrogen into ammonia, to serve the ~40% of US ammonia consumers who are within 100 miles radius of their plant.
A brilliant project, of great decarbonization benefit- but sadly, not scaleable to ever be a major source of hydrogen in terms of world H2 consumption. Replacing the 90 million tonnes of H2 we’ll need post decarbonization, at least initially, by such a process, would make 270 million tonnes of carbon- more than 10x the world market for both carbon black and graphite combined. While some are betting that throwing away 1/2 the energy and 3/4 of the mass of the feedstock will be paid for by the greater ease with which carbon may be buried relative to burying CO2, the jury’s still out on that. This process has the euphemistic tag of “turquoise hydrogen”. How black that turquoise is, depends on many very project-specific factors including methane leakage and the carbon intensity of the electricity used to run pyrolysis.
We could also switch from SMR to another process- oxy-blown autothermal reforming. That process is commercial already, being used in methanol and Fischer-Tropsch plants to make high CO:H2 syngas mixtures. It is less efficient than SMR if the target is pure hydrogen, but (nearly) all the CO2 ends up at high partial pressure in the syngas stream, making higher % captures much easier than with SMR. I will write about this in part 2.
We could also use electric heating, or burn product hydrogen, in the tube furnace of the SMR. The former, called E-SMR, is already under development by several companies, but again has limitations to the ultimate CO2e achievable due to methane leakage and CO2 generated from gas purification. The latter is just a way to burn up money in my opinion.
Finally, I will leave you with the single most authoritative, comprehensive and accurate review of the objectives, practicality and real motivations of carbon capture and storage that I’ve seen. Warning, it may make you laugh, and then cry, and the language might make even a sailor blush a bit.
Disclaimer: I’m human, and hence can easily misinterpret things, make mistakes, push the wrong button on my calculator etc. If you find errors in what I’ve written, and can show me with references or calculations where I’ve gone wrong, I will correct the text with gratitude.
If you can’t find anything wrong with what I’ve said other than that it makes you unhappy, or worried about your continued employment, then perhaps you need to reconsider things a bit. If it makes you angry enough to yell at my employer, Spitfire encourages you to try!
Most of us find waste to be viscerally repugnant. The smell and even the appearance of garbage revolts us. And yet we all generate it, in seemingly endless quantity.
In “developed” (rich) nations, we therefore have built extensive systems to get this repugnant material out of sight, and hence out of our minds, as quickly as possible. Sure, many of us dutifully separate our waste at source into the compartments required by the local waste authority, and sometimes that makes us feel good. But we’re left with a lot of questions:
1) Is the effort to separate waste at source, worth the bother? Not just the effort, but the energy to collect physically separated materials at source- is that a net environmental improvement?
2) What happens to the waste after we dispose it and it disappears from our consciousness?
3) We hear about waste from developed countries being “shipped overseas”. Is this a disposal strategy? Are we paying others to improperly dispose of our waste?
4) Wouldn’t we be better off to just burn the whole works? Or if that doesn’t sound appealing, couldn’t we do something “smarter” than burning, to harvest the energy contained in that waste for beneficial uses?
I’ve learned that “deep dives” into complex and important topics like this, tend to bore people and don’t get read. So I won’t be diving deep into this one- I’m leaving most of these complex questions unanswered! I just need to make a few quick points, based on decades of experience working on “waste to energy” type schemes of a bewildering variety of sorts. Because frankly, “waste to energy” and “waste to fuels” projects and proposals are popping up now like dog strangling vine on my farm. Whereas the dog strangling vine is just a pure green menace, waste to energy project proposal are seen as a chance to kill two birds with one stone- to deal with the smelly, unsightly, land-consumptive and potentially GHG emissive problem of waste landfills, while at the same time, making some energy that we need.
The problem here is that it sounds too good to be true. Because it’s not true. Or, more accurately, it is true in such a limited set of circumstances that it’s basically the exception rather than the rule.
Municipal solid waste (MSW) is an extremely heterogeneous mixture which varies in composition from place to place, from time to time, and as a result of the policies (or lack thereof) of the municipalities responsible for providing waste disposal as a public service. In places where waste source separation isn’t practiced at all, the waste stream contains a lot of materials that can be, should be, and in most other places, ARE recycled. In some cases, some of these materials aren’t source separated, but rather are separated manually or by machinery at the waste handling facility or transfer station. Let’s talk about groups of materials in general terms and consider them one by one.
Metals
Metals are sorted out because all metals are highly recyclable, and recycling them reduces GHG and toxic emissions dramatically relative to making fresh pure metals from their native ores. Of course only reduced metals in solid form (i.e. cans) are readily recovered by sorting.
To give you an idea: a typical aluminum can in 2014 weighed 15 grams. Aluminum has an embodied energy on the order of 200 MJ/kg, which means that a can has about 3 MJ of embodied energy associated with it. That’s about the same as the same can, 1/3 full of gasoline. Even with recycling, aluminum represents about 11.5 kg of CO2 emissions per kg. Anybody wasting aluminum cans needs to have their head examined if they also claim to care about the environment. Those thinking that it makes sense to turn aluminum, made from aluminum oxide by electrolysis, into hydrogen, are really energetic vandals.
Other Inorganics
There’s a lot of non-degradable, non combustible stuff in the average MSW stream. Lots of dirt, concrete, brick, rock, gypsum etc. from demolition.
There’s also a lot of glass and ceramic materials. The former are recyclable- the latter, aren’t. The best you can do with waste ceramics is grind them up and use them as a replacement for sand or gravel in concrete.
Wet Organics
This is food and yard waste, diapers, pet waste and the like. And frankly the only thing that makes sense to do with this stuff is to remove it at source and not landfill it. When you landfill wet organics, you encourage anaerobic degradation which converts the waste into biogas- a nearly equal mixture of CO2 and methane, the latter being 86x worse than CO2 on the 20 yr horizon in terms of global warming potential (GWP).
Paper and Wood
Same deal- paper and wood need to be source separated, but not because of the risk of biodegradation primarily. While paper is compostable, it’s not readily degradable in a typical anaerobic landfill. I’ve personally seen newspapers which were buried in landfill100 yrs ago that were still perfectly legible. While some biodegradation does happen in landfill, landfills are not designed to be bioreactors- quite the opposite in fact.
Paper is, however, of fairly high value for recycling, particularly cardboard and and paperboard. Recycling corrugated cardboard is an environmental no brainer. Cardboard is a high value material and even businesses which really don’t care about the environment at all, collect cardboard separately for recycling because it reduces their waste disposal costs. And wood, meaning lumber and the like rather than yard waste, can always be made into paper. Wood demolition waste is already harvested for this purpose in some locales, if it can be properly source separated. And of course if there’s a surplus, both can be burned as a solid biofuel.
Plastics
Plastics are nearly 100% of fossil origin. While they can be recycled, how much they are actually recycled depends on the nature of the plastic, the nature of the source collection (which determines how clean and how hard it is to sort), whether it’s a thermoplastic or a thermoset such as those used in composite materials and rubber (thermosets are basically not recycled, because recycling them requires the breaking of chemical bonds which don’t come so easily unstuck), and of course, what purposes the waste can be put to. Recent reports put the average of plastic recycling around 9%, which is far from stellar.
PET, the material used in beverage bottles, is very easily recycled mechanically and is fairly easy to source separate. However, just like with metals, we don’t generally recycle PET bottles back into PET bottles. Rather, we make PET bottles into things like carpet fibre, which don’t care about thinks like leachable content, colour and transparency quite as much as a clear food grade beverage bottle does.
However, the largest volume plastics are polyethylene (PE), polypropylene (PP) and polystyrene (PS). These materials, though readily mechanically recycled, are often used in the form of films, foams or thin-walled goods which can come back from consumers very mixed, dirty, coloured and otherwise hard to separate. And while you can make SOME goods out of PE/PP blends, most uses require quite pure material. Accordingly MOST PE and PP and most PS foam are not in fact recycled, but rather are landfilled.
There are myriad of other plastics, used either alone or in layers with other materials to provide the desired properties. Some like polyvinylchloride (PVC), are at once extremely valuable and useful and also basically a bomb, waiting to go off when you do the wrong thing at the end of life of that plastic material. And there are a myriad of uses for all those plastics, varying from inarguably dumb single uses like tie hangers or individual wrappers for plastic cutlery, to convenient but questionable uses like plastic grocery bags, to life-saving uses like IV bags, catheters, oxygen tubing, disposable syringes and the like.
When you compare the LCA data for plastics against materials they compete against in the marketplace for similar uses (such as paper, glass, aluminum or natural fabrics), plastics tend to come out on top. They use less energy and water, weigh less, have superior properties, and can be recycled. They can also sometimes save giant amounts of other waste- the thin PE wrapping on English cucumbers comes instantly to mind. This wrapping reduces the waste of cucumbers from field to table by at least 50%- a reduction in the mass and impact of waste of around a thousand fold. My friend Chris DeArmitt is a great source of the research into this topic- he knows more about it than just about anyone.
But of course, we all love to hate plastics. With some good reasons, and some bad ones. They are over-exploited in packaging. They have become so extraordinarly inexpensive that they have come to exemplify “cheap”, non-durable, consumptive and wasteful by virtue of the many dumb uses we’ve come up for them- which sadly people in the marketplace have rewarded by buying. Many plastic products are optimized for cost and aesthetic function, not for recyclability. And they enable convenience that suddenly seems mandatory- something you can’t opt out of without trying very hard indeed.
Energy From Waste to the Rescue!
The usual pitch for a “waste to energy” scheme is as follows:
get rid of the cost and inconvenience of source selection
eliminate the problem of methane generation in landfill
offset some fossil burning
save precious land by reducing landfilling
Who couldn’t love those things!
The Devil in the Details
As usual the devil lurks in the details.
First of all, we really need source separation for a few reasons. First, getting people involved in source separation helps them focus on minimizing waste generation. Second, it improves recoveries (dramatically) of the highest value, most energetically favourable materials to recycle, i.e. metals, carboard/paperboard etc.
Secondly, waste to energy isn’t the highest value use of the wet organic content. That material contains some energy, but it also contains a lot of water. Burning, gasifying or pyrolyzing waste (heating it up in the absence of oxygen), requires us to boil off all that water, and that takes a lot of energy. In net terms, most of the energy in the wet organic fraction, is needed just to provide the energy to boil off the water it contains. In net terms therefore, MSW which has been source separated for recyclables in even a prefunctory way, doesn’t contain ANY net energy of biological origin.
There’s an alternative which doesn’t mind the water. It’s anaerobic digestion, to produce biogas. That’s what we do in Toronto with our green bin waste.
But there’s still lots of energy in that MSW, right?
Yes. Even moreso if you don’t source separate the waste…
Sadly, that energy is waste plastic. All of which is of fossil origin.
MSW is therefore, in net calorific (heat content) terms, almost entirely a fossil fuel.
Finally, when you heat up waste materials to burn, gasify or pyrolyze them, you carry out chemical reactions which can produce emissions of significant toxicity, carcinogenicity, and leachate toxicity. It is not uncommon for a waste incinerator to dramatically reduce the volume, but to much less dramatically reduce the mass of feed waste materials- but to also render that material leachate toxic whereas the feed material wasn’t leachate toxic. That means that the process of burning “mobilizes” species that can leave in the (nearly inevitable) leachate which must be collected from the bottom of the landfill and treated prior to being disposed. That adds both cost and environmental impact that could be avoided. Incineration has to be made less energy efficient to cope with these toxic materials, both as a result of manipulating combustion conditions to avoid generating the worst species, and by virtue of energy used to scrub out or adsorb/desorb the toxic materials that are produced.
Waste to Fuels- Incineration in a Sexy Green Dress
Of course people have pictures in their heads of incineration that are very unpleasant, and some of that is unfair to incineration. Modern incinerators can generate quite clean exhausts, well scrubbed of toxic chemicals- if at the cost of generating only a fraction of the energy contained in the feedstock as a result. But that’s not the problem.
Ms Waste to Fuels- hot stuff, as she’s incineration in a sexy green dress!
The problem is the plastic.
The problem is the energy derived from the fossil origin materials in the waste stream.
The problem is the needless dumping of fossil CO2 into the atmosphere.
Since the net energetic value in the waste is of fossil origin, the waste itself is, in net terms, a fossil fuel.
Accordingly, some greenwashing is needed to recondition the image of waste to energy schemes, by dressing incineration up in a sexy green dress called “waste to fuels”.
By converting part of the energy and maybe even some of the embodied carbon in the MSW feed, into a new fuel, proponents hope to you won’t see incineration under its new clothes.
These schemes are varied, but they usually involve converting waste to simpler chemical by means of endothermic (heat-consuming) reforming reactions by processes called pyrolysis or gasification, which differ only in degree, energy input and desired suite of products. In both cases, heat, usually generated by burning part of the waste feedstock or part of the products or byproducts, is used to break big molecules into smaller ones. Sometimes, oxygen or air is added to the feed to produce some of that energy right in the reactor, and sometimes it is produced outside the reactor and transferred into it via heat exchangers. Sometimes solid materials, often inorganic constituents of the waste itself, are used to help transfer this heat.
The typical strategy is to make either a very light gaseous material called synthesis gas, which is typically a mixture of carbon monoxide, carbon dioxide, hydrogen, sometimes methane, along with water vapour, nitrogen, and acid gases like hydrogen chloride, hydrogen sulphide etc. (remember, waste is very heterogeneous- and it’s going to contain some PVC, some brominated fire retardants, some fluoropolymers…a host of nasty molecules can result when you break these bigger molecules down). The syngas can then either be burned for energy in a turbine after some basic cleanup, or it can be cleaned up much more thoroughly and converted over catalysts to molecules like hydrogen, methanol or Fischer-Tropsch liquids (waxes, diesel etc.). These materials, including the hydrogen, are generally intended for use as fuels. Yields vary depending on the feedstock and process and conditions, but let’s be clear: a considerably smaller fraction of the energy in the feed material is converted to these secondary fuels than would have been obtained if you simply burned the waste in an incinerator.
What happens to the fossil CO2?It all ends up in the atmosphere. When hydrogen is the product, all that CO2 goes to the atmosphere directly, and more CO2 is released per kg of hydrogen produced than if you started with fossil methane instead. That we can say with certainty just from looking at the nature of the feeds: plastics, the major energetic content of MSW, have a typical formula of (-CH2-), whereas methane has a formula of CH4. The higher the C:H ratio of the feed, the higher the CO2:H2 ratio in the products. The result might be better than coal, but is definitely worse than methane. The only difference between the two is that fossil methane comes along with a burden of production and distribution methane leakage that the plastic waste doesn’t. Depending on where you’re making the “black” hydrogen from fossil methane, that leakage can vary between a significant and a very significant CO2e impact, given methane’s GWP of 86x CO2 on the 20 yr timeframe. Sorry folks, but that alone isn’t going to get you my sympathy for making hydrogen from garbage. It’s going to be close to a wash, at best.
Can You Make it Worse?
Sure. You can do the source separation, separate out the waste plastic, and then gasify it. That’s even worse!
Why is it worse?
Because the alternative would be to simply landfill the waste plastic.
Waste plastic degrades when left in the environment, losing mechanical properties and fragmenting into smaller and smaller pieces. Those degradation processes however are driven by two things: oxygen, and sunlight. Sunlight provides the high energy needed to break the bonds in these synthetic materials, that natural processes like biodegradation were not evolved to break apart. And oxygen can react with the polymers both in the dark and in the light.
What happens when we bury plastics in a landfill? Those degradation mechanisms simply stop. There’s no more driving force for the molecules to fall apart, so they don’t. Waste plastics in a proper anaerobic (covered) landfill are stable for millenia. They don’t break down into microplastics. They don’t leach into the groundwater. They just stay there. Their environmental impact simply ends.
As does their fossil carbon content. It stays there. Sequestered. Durably.
For millenia.
What We Should Do Instead
We should stop believing in ideological fantasies of “circular economy”. We should instead begin to think about optimal recycle. And we should focus on making lots and lots of truly renewable and low emissions energy, because as we do that, not only will we feel less need for fuels made from garbage and waste plastic, we will also increase the optimal amount of recycle- because we will reduce the environmental impact arising from the energy used to drive recycling.
What does an optimal recycling system look like for plastic waste?
Here’s my view:
1) You start with good public policy. Policy which looks holistically at the use and end of life of products, using reliable, disinterested 3rd party LCAs as a guide. Stop making decisions on the basis of the “natural is better” fallacy, like the totally idiotic decision to replace polypropylene drinking straws with waxed paper ones. The waxed paper ones are inferior in function, alter the taste of the beverage, aren’t durable, can’t be re-used, use more water and create more emissions in manufacture and transport than their PP cousins, and yet neither PP nor paper degrade in a landfill. The only, minor benefit of mandating paper straws is that the paper ones degrade a little faster when they’re deposited as litter. Litter makes up perhaps 1% of our disposed waste packaging materials in developed nations. Doing worse with 99% of a product to partially mitigate the impact of 1% of its end of life disposal is not sensible.
Better still: don’t offer a straw of any kind unless it is asked for.
2) Mandate “deposit return” for goods which otherwise don’t end up recycled well. This would apply to goods ranging from beverage bottles to cellphones. Users are quite willing to return goods for cash if there’s cash to be had. This generates cleaner, better sorted waste streams for either re-use or recycling.
3) Maximize mechanical recycling of plastics. And don’t concern yourself about the fact that most recycling- of plastics and of metals and other materials, is really “down-cycling”. Just as we don’t recycle pure copper wire into copper wire again, we don’t recycle PET bottles into bottles again. Why not? Because down-cycling copper wire to copper pipe, and PET bottles to carpet fibre, makes more sense energetically.
4) When you have a stream of mixed plastics that are partially degraded, you can do a limited amount of chemical down-cycling to make materials such as waxes, asphalt extenders, printing inks and the like. Doing this makes sense, but will only be a limited endpoint for the plastics.
5) Most of the degraded, mixed and dirty plastics will end up being useless after they’ve been optimally recycled. How should we deal with them? We should bale them and then bury them in properly constructed landfills. They represent the cheapest, lowest impact, lowest risk post-consumer fossil carbon sequestration strategy imaginable. All you have to do is not burn them.
Finally: if you don’t have space for landfill, you have two choices: work harder at steps 1-4, or pay somebody else to landfill the waste plastic for you.
Disclaimer: this is not a thorough examination of the topic, it has been kept brief so that people might read it. This is an enormously complex topic involving the interrelation of society, technology and values, environmental impact, decarbonization and economics.
I’m not at all saying that there can never be a “waste to X” or even a “waste to energy” scheme that makes environmental sense. I’m specifically attacking waste plastic or MSW to energy or fuels schemes, because I think it’s quite clear they aren’t good waste management practice and aren’t in the interest of decarbonization either.
If you don’t like what I’ve said, that’s OK. If you think I’ve materially erred, that’s entirely possible as I’m human and make mistakes like anyone. Provide good references demonstrating where I’ve gone wrong and I’ll correct my piece with gratitude for your input.
Anthropogenic global warming (AGW) is a real risk for future generations including my own children. It’s a risk I’ve personally taken seriously, and have taken personal action against, since the late 1980s when I was in university. And while we’ve seen some extremely positive developments in the past 30 years such as the creation of new industries to generate wind power, solar power, electric vehicles, biofuels, LED lighting etc., this has barely moved the needle on the root causes of AGW: fossil greenhouse gas (GHG) emissions and land use changes made by humans.
Why have we not taken more action? We knew about AGW thirty years ago- the science was quite solid even back then. The reality is, we ignored the science because many people- ordinary voters AND the people in power who report to them- refused to believe it. Many continue to do so to this today. And why is that? Human motivations are complicated, but I see two key root causes. One is that the worst harms from AGW aren’t likely to be experienced by the generation making the emissions, but rather by future generations, i.e. people may love their children, but not enough to avoid spending their inheritance in this sense. The other is that they’ve been fed a series of lies, in part by parties interested in profiting from the status quo as long as possible, which allow people to cling to a shred of doubt about the underlying science which is, frankly, not supportable by the facts.
The risk of AGW hinges ultimately on three facts. These are indeed facts- things we know, based on measurements- generally multiple measurements which compare favourably with one another. Each of the three facts also has sound theoretical underpinning, meaning that we not only know them to be facts, but we know both why they’re facts and also why they’re important. And these three facts are not the subject of credible dispute in the scientific community. They are not the topic of active discussion in the peer-reviewed journals on the subject, which has another name- the repository of the current state of human knowledge on the topic.
Here are the three facts, one by one, along with peer-reviewed scientific references, or more accessible references which themselves refer to the underlying scientific papers, which will allow you to assure yourself that I’m not just making this up.
Fact #1: Atmospheric CO2 Concentrations Have Increased
We started burning fossil fuels in earnest in the 1720s when the first, highly inefficient steam engines were invented. These engines were in part used to power pumps- in coal mines. Steam engines were in that sense a recursive technology, i.e. one that enables and magnifies its own success. The burning of fossils freed us in a sense from what was at the time, the terrible burden of energy sustainability without modern technology. We no longer needed to balance our need to stay warm against the rate at which trees grew to make firewood for us as just one example.
For the millennium before that, atmospheric carbon dioxide (CO2) concentrations were stable, bouncing around near 280 ppm. They did change a bit as we de-forested much of Europe to provide firewood, through the so-called Mini Ice Age and Medieval Warm Period, and then as we hewed down North America’s forests and burned them too. But for 1000 years, the concentrations remained more or less stable.
This means that the carbon cycle was more or less in balance. Flows of CO2 and methane up into the atmosphere from respiration of animals and plants, desorption of CO2 from the oceans, decay of organic matter, emissions from methane seeps and volcanoes etc., were in balance with flows of CO2 out of the atmosphere due to photosynthesis, dissolution into the oceans, soil organic carbon generation, oxidation of methane to carbon monoxide (CO) and CO2 in the upper atmosphere, weathering of silicate rocks and the big final sinks- oceanic sequestration, i.e. the conversion of CO2 into carbonate rocks and the permanent burial of oceanic sediments containing biomass. That both the natural up- and down-flows of CO2 and methane are positively massive in fact doesn’t matter- what matters is that they were in balance.
But when we look at the concentration of CO2 in the atmosphere, as measured in bubbles of air trapped in ice cores primarily, what we see is that CO2 concentration was surprisingly consistent: from the Law Dome ice core data, the precision of the CO2 concentrations is estimated at +/- 1.2 ppm, and the observations over the pre-industrial period to about 1006 AD were 275 to 284 ppm. The concentrations started to rise as we started to burn fossils in earnest.
Since the 1960s, independent groups have been continuously monitoring CO2 concentrations in the atmosphere, most notably at the Mauna Loa observatory in Hawaii. The concentrations show a continual increase year after year, with a “sawtooth” of small seasonal changes up and down each year. The “sawtooth” arises from changes in seasons on Earth- there is more photosynthetic plant life in the northern hemisphere than the southern, so when the north is in summer, CO2 concentrations drop a little- only to rise again in winter.
CO2 concentrations have recently reached 415 ppm- a concentration not encountered in the past approximately 1,000,000 years. CO2 has never been this high since there was anything recognizable as a human on the planet.
CO2 has gone up, rapidly, from a stable level, and continues to increase as I write this. So, sadly, have the concentrations of methane, N20, and other so-called “greenhouse gases” (GHGs).
This is a fact, not something a credible person can argue with.
Fact #2: We Caused The CO2 Increase, Primarily By Burning Fossils
It isn’t sufficient to say that CO2 went up “suspiciously” as our emissions of fossil fuels went up- that is an argument from correlation which does not prove causation. What we can say is that the increase in CO2 concentration is consistent with the theory that fossil fuel burning caused this rise, but though it looks suspicious, this alone absolutely isn’t sufficient proof.
(Aside: if you care at all about AGW, or renewable energy, or both- reading the late David Mackay’s brilliant work at www.withouthotair.com from beginning to end is your first minimally necessary step in educating yourself about the issues we’re up against in my opinion. It’s very accessible and its conclusions very clear: dealing with AGW is absolutely necessary but it will be a very challenging problem because we use a lot of energy and hence burn a lot of fossil fuels right now)
There are however two measured facts which prove conclusively that the new CO2 in the atmosphere is primarily there as a result of our burning of fossil fuels.
The first is simple carbon mass balance accounting. We can fairly accurately estimate how much fossil fuel we’ve burned, since fossil fuels a) cost money and b) are taxed. A scientific accounting of the amount of fossil fuel burning does demonstrate that not only did we produce enough CO2 to cause atmospheric concentrations to rise by the amount they did (proven by measurement above), but we actually emitted TWICE THAT MUCH:
Where did the other half go? Some of it went into the oceans, as would be expected by anyone who understands a little physical chemistry. As CO2 dissolves in water, the pH of the water decreases. Acidification (decreasing pH) of the surface oceans has indeed been measured, and has occurred because of the increased CO2 concentration in the atmosphere. This too is of concern to ocean life such as corals and shelled sealife which rely on carbonate fixation as part of their lifecycle.
This animated visualization of the carbon cycle, showing how carbon moved from fossil reservoirs into the atmosphere and then down again into the oceans and biosphere, is most helpful in demonstrating what happened:
The 2nd proof of the anthropogenic origin of the new CO2 in the atmosphere is isotopic measurements of the carbon in atmospheric CO2. The ratios between stable 12^C and 13^C and radioactive 14^C (continuously generated by cosmic rays and continuously decaying to nitrogen) have long been known to have been affected by the addition of ancient carbon to the atmosphere. Living things, while living, have roughly the same ratio between 14^C and 12^C as the atmosphere. But fossil fuels have been dead and separated from the atmosphere for a long time- many, many half-lives of 14^C, and hence are nearly free of 14^C. The result of our fossil burning has been a gradual decrease of the 14^C to ^12C ratio in the atmosphere. The ratios of 13^C to 12^C also demonstrate the same thing- the new CO2 is of fossil origin- it hasn’t desorbed from the oceans, been released by rotting biomass etc. The following references are provided if you want to learn more.
It should be noted that the CO2 emitted from volcanoes is also low in 14^C- but the amount emitted by volcanoes is actually quite small relative to the amount emitted by humans as a result of burning fossil fuels. Two gigantic volcanic eruptions in the recent past- Mt. Pinatubo and Mt. St. Hellens, as examples, produced barely a blip in global CO2 concentrations measured at Mauna Loa. Let that sink in for a moment: we fossil fuel-burning humans are by far the biggest volcano on earth, in terms of emissions.
Again, that the new CO2 in the atmosphere is primarily a result of us burning fossil fuels and dumping the resulting CO2 into the atmosphere, is not in credible scientific dispute. It’s a fact, based on multiple replicate measurements which agree with one another. It’s a fact that we’ve known about for a long time too.
Fact #3: Extra CO2 (and other GHGs) Causes Climactic Forcing
This one again is not a supposition- it is a fact, arising from both an understanding of basic physics known since the late 1800s, and direct measurements.
Most of the atmosphere is NOT CO2. The atmosphere consists mostly of nitrogen, oxygen, argon and water vapour. CO2 is a minor constituent at only 415 ppm or 0.04%. But everyone should realize that a small concentration of something can have an out-sized effect. If you don’t believe this, breathe some air containing a very small amount – say 400 ppm or 0.04%- of carbon MONoxide…but please don’t do that! You should already know the outcome- and hopefully have a CO detector in your home too, to make sure you don’t do so by mistake.
(Note: CO2 is also toxic- carbon intoxication symptoms start at concentrations above about 5,000 ppm or 0.5%. That’s a far higher concentration than the atmosphere will ever get to, but it certainly can get that high in spaces particularly underground with poor ventilation.)
That is NOT to say, however, that CO2 is an unimportant constituent! It, along with water and solar energy, is one of the three primary fundamental building blocks of life on earth. It isn’t “plant food”, in exactly the same way that cement blocks aren’t food to construction workers. It contains zero useful chemical potential energy- a fact which makes it the desired product of processes intended to liberate chemical energy such as combustion or respiration. It’s merely a material that plants can collect and use solar photochemical energy to convert, along with water, into biomass. Having more building blocks at hand when CO2 concentrations are higher, simply means the plant has to expend less energy to build a given amount of biomass.
CO2 is also a strong absorber in the infrared. The earth receives solar energy at a range of wavelengths ranging from ultra long radio waves to high energy X rays- with the peak of the energy emitted in the visible wavelength band between 400 and 700 nm.
The magnetosphere and the upper atmosphere fortunately filter out a lot of the nastier, most damaging short wavelength radiation from the big fusion reactor in the sky before it gets to us on the surface.
Some is reflected, but the earth absorbs the remaining solar energy, with plants capturing only a small amount of it to store in the form of chemical potential energy. The rest, per the 1st law of thermodynamics, has to go somewhere. And that’s what happens- it ultimately goes back into outer space from whence it came. Because the earth is quite cold relative to the ball of radioactive fusion plasma in the sky, it re-radiates the energy absorbed by the sun not as short-wavelength UV or visible light, but as infrared (IR) light. The average solar energy input, minus whatever is stored in the form of biomass and hidden away from being eaten and respired again to CO2 and water, raises the average temperature of the earth until the amount of heat leaving through the atmosphere equals the amount falling on the earth.
Of course if this were all that was happening, the earth would be a snowball and humans wouldn’t exist…
Instead, the atmosphere absorbs some of the infrared energy radiated by the earth, and re-emits it back to the earth, giving us a 2nd exposure to some IR light that would otherwise be transmitted again to the blackness and cold of space. This partial absorption and re-emission of the radiative emissions of heat from the earth, back to the earth, by gases in the atmosphere, occurs mostly as a result not of CO2, but of water vapour. Water is also a strong IR absorber- and is the earth’s predominant “greenhouse gas” (GHG).
…but before you start to worry about water vapour emissions from your shower or teakettle warming the planet, remember that water vapour is in rapid physical equilibrium with liquid water in the oceans, soils and biosphere. The mean water vapour content of the atmosphere therefore depends on the mean global temperature, and is not meaningfully affected by human emissions of water vapour to the atmosphere.
The absorption spectrum of water vapour and the other “permanent” gases in the atmosphere has a “notch” in it- a range of wavelengths through which IR light can escape unimpeded.
This is in part the reason that frost and condensation (such as dew) can happen when the air is at a bulk temperature higher than the dew point or the frost point. On a clear cloudless night, surfaces such as your car windshield have a narrow wavelength window through which they “see” the blackness of space at 4 kelvin above absolute zero- and hence can lose heat through this window, surprisingly dropping to a temperature lower than the ambient temperature. Special surfaces which enhance this re-emission are an interesting area of study for reducing energy consumption from cooling systems:
This notch in the IR absorption spectra of the normal constituents of the atmosphere is called the IR re-radiative “window”. And it turns out that CO2, methane, N2O and a number of other gases, absorb IR strongly in this range of wavelengths along with others. They always have done. And we’ve known this for a long time- ever since we were able to measure the IR absorption spectra of these molecules- since around the late 1800s. These GHGs narrow the IR re-radiative wavelength window into outer space, making the earth “dimmer” as an IR emitter and requiring the earth’s mean temperature to rise until it can shove enough IR through the remaining portion of the window.
Of course this means that if we add EXTRA CO2, methane, N2O etc. to the atmosphere, this will narrow the IR re-radiative window even further. And that, obviously, forces the climate – it requires earth to warm to satisfy the new balance between the in-flow and out-flow of energy. Input minus output equals accumulation, and if we restrict the out-flow of IR from the earth to space, the earth MUST warm to satisfy the new balance point.
It is also true that a doubling of CO2 does not result in a doubling of the resulting climactic forcing- it’s much more complex than that. Extra CO2 does have somewhat diminishing returns as a greenhouse gas. Contrary to the claims of many denialists, however, the effect of extra CO2 is not “saturated”- as one easily found peer-reviewed reference states:
“We conclude that as the concentration of CO2 in the Earth’s atmosphere continues to rise there will be no saturation in its absorption of radiation and thus there can be no complacency with regards to its potential to further warm the climate.”
Warming also increases the amount of water vapour in the atmosphere- remember, water is still the primary GHG. That is a powerful positive feedback.
Note that so far we’ve discussed only CO2- but in reality, humans have also increased the amount of methane and of N2O and other GHGs too through our actions and inaction.
Three Facts- Not In Scientific Dispute
These three facts: CO2 went up, we caused it by burning fossils, and extra CO2 narrows the IR re-radiative wavelength window, forcing the climate – these are not in credible scientific dispute. Nobody is arguing about the fundamental validity of any one of the three of them in the scientific literature. It’s not that they’re scared to, or worried about losing their funding if they did- it’s simply not worth arguing over because it is so well demonstrated as fact, consistent with all the data we know of. And if you hear anyone denying any of these three facts, the conclusion is clear: they’re either ignorant, or they’re lying – to you, to themselves, or both. It’s that simple.
This is not a matter of orthodoxy, it’s a matter of simple measured fact.
Three Facts = RISK of AGW
The three facts I’ve pointed out lead inescapably to the conclusion that there is a very real, fact-based RISK of global warming caused by human activities (i.e. AGW). There can be no other conclusion.
It is of course perfectly valid to then say, “so what?” Let’s say that we accept that CO2 went up, we caused it, and the extra CO2 forces the climate. The last bit of wiggle-room for either denial or skepticism remaining is to claim that the resulting forcing will be minor, and hence not a problem for humans or the rest of the biosphere.
How does one translate the risk of AGW, which is certain, to a particular amount of warming of the earth? We do know the temperature must go up as a result of the facts we know, but how do we know by how much it is likely to increase? And how quickly that will happen?
The answer is that the earth is a complex system, with many inter-related factors, all of which can affect the climate in one direction or another, to a greater or a lesser degree. Some of these effects occur instantaneously, like the changes in the IR absorption. Some happen on a timescale of days, others years, others centuries, and others, millennia or even longer. And many of them are very much predictable.
Science therefore must have recourse to models, to estimate the effect of the additional radiative forcing on the earth’s mean temperature. Those models have to be very complex to tell us anything meaningful and reliable. And unfortunately, there are no replicate Earths available for us to do tests on, with an accelerated timescale so we can see results soon enough to understand our model’s validity.
And that’s where some skeptics hang their hats- they make the claim that climate models are fundamentally untestable, and hence not reliable enough to use to draw any conclusions from.
That statement however, fails on two basic points:
1) There IS a system on which we can test the validity of our models. That system is our earth in its recent PAST.
2) Merely being unable to precisely estimate a risk, in no way absolves us from the responsibility to act to mitigate that imprecisely-quantified but otherwise certain risk. Any engineer who has ever attended a Hazop review understands this fact intimately (or shouldn’t be involved in Hazop reviews!)
Some throw up their hands and say that it’s impossible to make decisions such as bringing to an end the burning of fossil materials such as coal, petroleum and natural gas, with the discharge of the effluent to the atmosphere, on the basis of something as unreliable as a model of the earth’s climate. But these people do not understand how we engineers make decisions related to risk as we practice our profession. We have a duty to hold the public safety as paramount- and that duty does not allow us to simply throw up our hands and say, “prove it!” before we will take a mitigating action.
We engineers see risk as the probability of a bad outcome, multiplied by the severity of the bad outcome. Merely bad things which are likely to happen very frequently are a high risk. And truly terrible things- like raising the mean temperature of the earth by, say, four degrees Celcius in a period of a century or so? Those things don’t need to have a very high probability of happening before we MUST take action because the risk is too high.
Others argue that global temperature measurements are difficult, or have been “manipulated”, and hence the data against which the models’ predictions are measured are suspect. Global mean temperature is a very hard thing to measure, and a very noisy signal. It’s also slow to respond- something as large as the accessible portion of the Earth has an enormous heat capacity. But those people are either conspiracy theorists, who think scientists are deliberately lying about climate change in order to further their careers (rather than being the one scientist who blows open such a conspiracy and gets a Nobel prize…), or they’re ignorant of just how many different measures of, and proxies for, global mean temperature have been used to check the models.
While my fundamental opinion is that we should defer to the knowledge and experience of the people who actually study the climate as their principal area of study in their area of expertise, I have seen a few compelling things that demonstrate to me that the models are in fact on the right track.
Here’s the first one: a clever animated infographic which shows that alternative explanations of the rise in global mean temperature that HAS in fact been observed, do not explain the increase. This uses, as I mentioned, the recent past of the earth as a means to test these various hypotheses of why the temperatures we’ve observed have in fact increased by the amount they have done:
No, it’s not the sun- the sun’s output DOES affect the climate, as do orbital and earth tilt cycles. But those things doesn’t explain the increases we’ve seen this time around either.
It’s not aerosol emissions from pollution or volcanoes, ground-level ozone, deforestation/land use changes etc. It’s clearly a result of the increased concentration of GHGs in the atmosphere. The risk is real- it’s having results on the earth’s climate.
The 2nd is this graphic for which I can thank @Mark Tingay for posting repeatedly in response to AGW denialists’ comments here on LinkedIn. It shows the consistency of the models with the measured temperature data, expressed as the “anomaly”, i.e. the excess of the reference 1980 temperature that has been measured:
This is most up to date- from Gavin Schmidt’s Twitter feed. (He’s director of NASA’s Goddard Institute)
Both the models and the measurements of temperature have error bars on them, as does the risk resulting from the three facts I’ve discussed above. But here’s the key point: the error bars on these measurements and calculations do not extend to giving us hope of there being no effect, i.e. an effective risk of zero. And they certainly do not extend to giving us hope that we can continue to burn fossil fuels in the profligate way we’ve been doing for the past century or so, without the negative consequences of AGW.
We’re seeing rather clear, obvious evidence of those consequences even now- the temperatures have absolutely risen in a significant way. And it stands to reason, and to commonsense, that adding significantly more energy to a system like the earth’s climate, is going to have some serious negative outcomes- some of which, such as the melting of Arctic permafrost, themselves would be gigantic positive feedbacks on AGW, making it even worse. I’m not going to get into listing those impacts here- if you care to hear about the potential nightmare scenarios we could be generating for our progeny and theirs unless we smarten up and curtail our direct burning of fossils as fuels, you can find lots of that stuff elsewhere. Just ask that little Swedish girl that so many seem to be terrified and angered by. She’ll give you an earful- and yes, we all deserve it.
Many people who accept, perhaps grudgingly, the reality of the risk of AGW, are turned off the whole thing as a result of what they see as hyperbole used by those who want to convince us that AGW risk is a very serious issue which needs our prompt and serious attention. They react badly in particular to what they think is “alarmism”- for instance when someone says that we have less than 20 years to avert “global catastrophe”. I sympathize- the shrill rantings of uninformed people make me angry too, and I spend a lot of my time combatting the untruths, half-truths and distortions they are spreading on the Internet.
But it is important to clarify this one point: that we have limited time to avoid locking in potentially catastrophic warming. That point is consistent with the facts actually- but what isn’t being said, or perhaps isn’t being emphasized, is that they’re not saying that the catastrophic warming itself will be encountered in the next 20 years. It won’t be. The earth has a lot of heat capacity, so it heats slowly. It should therefore be no surprise that young people are most concerned about AGW and its effects- because they and their children will be the ones who live long enough to encounter them. We, their parents and grandparents, are not likely to be alive to experience the worst of those effects.
Final Thoughts About AGW and Conservatism
Sadly, some people are motivated to disapprove of AGW and pretend it’s not a problem out of a misguided notion of what it means to be “conservative” or “skeptical”.
Fossil fuels are a precious, finite resource- on the human timescale rather than the geological one. They are used to make ten thousand molecules and materials that are every bit as essential to modern life as energy is. And as someone who has helped people try to do this for a couple decades, I can say from first-hand professional experience that replacing some (many) of those molecules and materials with alternatives or substitutes derived from renewable resources is very difficult indeed- far more difficult than it is to make energy by renewable or non-emitting/low emission means.
Being “conservative” means valuing conservation, not being stodgy and unwilling to change or adapt, and certainly not being willfully blind toward new information when it comes to light. There is plenty of reason to conserve those precious, finite fossil resources for uses of highest value to humankind rather than squandering them as fuels. This would be true even if AGW were a total crock of horse effluent. Future generations will scold us not just for AGW, but also because we squandered their birthright in such a wasteful way and made their lives more difficult as a result.
Finally, being skeptical doesn’t mean rejecting anything you don’t understand. It certainly doesn’t mean relying on your current worldview entirely to inform you about what information you should accept as true and what you should reject as false. Being skeptical merely means being able to say “I don’t know” until you have sufficient proof to actually know. And there is no room for skepticism, whatsoever, in relation to the three facts which underpin the RISK of AGW. Your choice is to be either in denial of reality, or not. Please choose wisely!
Acknowledgements: thanks to @Mark Tingay and many others active here on LinkedIn for tirelessly chopping mutually inconsistent heads off the 9-headed hydra of climate change denial. Many give up, leaving the discussion floor to the denialists unchallenged and leaving the general public the view that there is room for doubt where there is none. It is a hard fight, but a worthwhile one.
Thanks also to Brian Dunning and this particular Skeptoid episode, which was the inspiration for this line of reasoning on my part. Skeptoid articles are fun to listen to, and give you the option to read instead if you, like me, read faster and more accurately than you listen:
DISCLAIMER: everything I say here on LinkedIn is my own opinion. And my opinion is not infallible- and is subject to change when presented with new data with good references. If I’ve made any errors here- and I likely have- then by all means message me or comment to my article here and let me know where I’ve gone wrong. Do it respectfully though- if you go ad hominem, I’ll block you- life’s too short for that kind of horseshit.
Finally, my employer, Zeton Inc., takes no opinion in these matters, does not endorse my statements, and loves what it does- designing and building pilot plants for the whole breadth of the chemical process industry. If you take issue with anything I say, please take it up with me and leave Zeton out of it.
UPDATED 25/06/2024, because LinkedIn messed up the formatting, deleted every apostrophe etc. How the hell does that stuff happen? No idea…but I’ve cleaned up the mess, and added a lot of links to new articles on related topics. And I’ve also admitted that my predictions about Ontario’s tendency to re-kindle a romance with boring old nuclear turned out to be wrong, sadly. Well, at least if we build nuclear, we won’t need to build quite so much gas- but it would take a change of provincial government to get us to do the more sensible thing and build more renewables and storage.
Oh Paul, you’re so critical! You just crap on other peoples green solutions, telling us why they wont work in your opinion! Where are YOUR solutions? Put up or shut up!
First Premises First: what are we trying to solve, exactly? Anthropogenic global warming. (Any denialist posts to this article will be deleted. Want to argue about AGW? Do it in response to my article on the subject!)
Toxic pollution that shortens peoples lives. That’s obviously bad too, and it’s long past time we dealt with it.
There are lots of others, but those are the two biggies.
Don’t agree that these are problems worth solving? Wondering what all the fuss is about, and why we don’t just keep burning fossils with mad abandon? Then please- do us a favour and just go somewhere else. Discussing solutions to problems with people who don’t believe the problems are real is just a total waste of time. We’ve been doing that for the past 30 yrs, and there isn’t another 30 for us to waste.
What Must End?
We have to stop burning fossils as fuels. Not immediately, not completely, but eventually, over time. We need to stop burning all of them, but we can start with the worst one- coal. We don’t need to wait, but we can certainly focus on them in order of decreasing C:H ratio. That’s not a bad way to look at it, in weighted terms, i.e. looking at both toxic and fossil GHG emissions. Not pretending that methane leakage isn’t a problem, but not focusing ONLY on GHG emissions either.
We don’t need to replace the primary energy we use today in the form of fossil fuels though.
What we want here is to accomplish as many of the benefits of modern life as we can, just without burning fossils on purpose to do it. We don’t need to burn fossils to move people around. Nor to have comfortable homes. Nor to provide lighting. Nor to provide healthy food, in quantity and variety.
We do burn fossils for all those purposes, in part or in total. Why? Because they’re cheap. And they’re cheap, in part, because we don’t charge much to use the atmosphere as if it were a giant, limitless public sewer.
SOLUTION #1: Carbon Pricing
That’s no solution at all, Paul! Yes, you’re quite correct on that point. Its not a solution in and of itself. It is, however, the absolutely, minimally necessary precursor to ANY SOLUTION to the problem of AGW.
Period.
Don’t agree with me? You’re not being serious, or you’re ignorant. Did that sound harsh? I meant it to. We need steep, increasing, durable, sustained and ultimately VERY HIGH carbon taxes. North of $150 USD per tonne of CO2e. And yes, they MUST apply to fossil methane leakage too- except at 86x CO2.We need those carbon taxes to be investment grade. Otherwise, you’d be an idiot- as a business or an individual- to make the expensive, long-term capital investments necessary to avoid those CO2e emissions.
They need to be international, so that laggard or cheater nations don’t get a trade advantage by not imposing their own taxes. And because you know some nations WILL be laggards or will try to cheat, we also need carbon tariffs on the goods and services of laggard or cheater nations. Doing anything less will eliminate the willingness of people to bear being taxed. Everybody has to pay the tax, or no one will.
Carbon taxes are more efficient than cap and trade schemes, and harder to defraud. And while they are necessary, they are not, by themselves, sufficient. They will need to be paired with regulatory controls, or else the tendency for demand to be somewhat inelastic to increasing price will take over.
SOLUTION #2: Electrify Everything
Well, not everything. Just absolutely everything we can. As soon as we can.
And we need to do that, again, in order. Starting with all the places right now where we take an input of heat (chemical energy) but require an output of work (mechanical energy). That means transport, as well as the obvious: we have to stop burning fossils to make electricity.
Canada has the problem of burning fossils to make electricity basically already licked. Yay Canada! About 80% of us have access to a grid which is 40 g CO2/kWh or less. The remaining 20%, in Alberta, Saskatchewan and some of our smaller eastern provinces, are also working hard to decarbonize electricity- at least by means of the half step of transitioning from coal to gas.
But all of us will need to make a lot more electricity using renewable or non-GHG emitting sources. That means lots more wind, solar, geothermal, hydro, biomass, tidal etc. And in some places, it also means lots more nuclear. But beware- nuclear won’t be cheap, or fast. Building electricity based on a 10-15 year forward demand forecast is going to get it wrong, and getting this wrong, can be very expensive.
SOLUTION 3: Over-Build Renewables
Wind and solar were once expensive, and totally dependent on subsidy. Not any more! They’re now the cheapest kids on the block, and not by a small amount. When they’re available, they’re cheaper than any other way to make electricity. And they’re not done getting cheaper, either.
All electricity production technologies must engage with that fact. Unless governments actively PREVENT the use of solar by homeowners, and prevent the use of wind power, grids everywhere are going to have to learn to cope with intermittent renewables eating part of their pre-paid lunch.
Wind and solar are, of course, fundamentally intermittent. Solar has predictable daily and seasonal average variation, and unpredictable weather-related variation. Wind has variability which again depends on location and the seasons- but fortunately, at least the wind blows at night some of the time- and may blow more in winter than in summer in some locales. The combination, therefore, is more valuable than using either in isolation.
Wind and solar do however have a variability which results in annualized average capacity factors which are less than 100%. They don’t make power steady, 24/7/365, nor when we need power. In Toronto, solar’s average capacity factor is about 14%, meaning that a 1 kW nameplate solar panel makes only about 1200 kWh in an average year, not 8760 (i.e. 24×365). And Toronto is SOUTH of most of Germany, in case you’re wondering.
As for wind, its capacity factor varies depending on location and turbine size. Big turbines get access to steadier winds, as do offshore locations. Capacity factors for onshore wind are on the order of 30%, and for big turbines offshore are around 45%. For comparison- which is very important here- hydro power which is often talked about as if it were steady year-round, also has an annualized capacity factor of only about 43% (EIA, US, 2018) and coal, only about 53% (same source, 2018) (UPDATE- capacity factors for coal continue to fall- even in China!).
Nuclear is the stand-out at about 93% capacity factor- but just like coal, its capacity factor isn’t a feature of its reliability to make power when needed, but rather a factor of how its owners operate it. Nuclear is expensive to build and has a near-zero fuel cost, so it must be run as close to full capacity as possible to amortize its cost over as many kWh as possible.
Coal, on the other hand, makes more money running when power is needed, but cannot turn on and off in a matter of minutes- so sometimes it is more economical to just not run the plants. Coal’s capacity factor in 2013 was 60%.
The low-ish capacity factors and the moment to moment variability of wind and solar make some dubious about building a future on these unreliable energy sources. And it certainly makes them challenging to use economically for some purposes- making chemicals like hydrogen being the obvious one.
There are two ways to solve this problem however. The simple-minded one, which many assume for some reason to be the only practical solution, would be to pair renewables with storage. If we need 1000 GWh of electricity, we build enough wind and solar to make say 1100 GWh of wind and solar over the year, and then use storage to fill in all the mismatches between supply and demand. That is, frankly, just nonsense.
The obvious solution with wind and solar getting cheaper by the minute, is to simply build more than we need, and spill (curtail) the rest.
Unlike a thermal power plant, it costs nothing to stop making power from a solar panel or a wind turbine. A solar panel can be making full output and then making ZERO output a millisecond later- all you need to do is switch it off! It doesn’t break anything- there’s no water treatment to run, no steam to condense or vent. There’s no cost. It merely means that you don’t get to amortize its capital cost over quite so many kWh per year, so each kWh gets a little more expensive.
If it costs 1/2 what were paying now for electricity, the obvious solution would be to build 50% more than what we need, use the surplus if we can, but not cry a tear when we don’t need it. If it costs 1/4 as much…and it will…well, you get the picture!
I already do this on my farm. We are too far away from power poles, and use too few kWh per year, to make a grid connection worth having. So we have enough panels to make the power we need at peak during the day, we store a bit for use at night in batteries, and we just dump the rest. Its by far the cheapest solution. Its far cheaper than having fewer panels and MORE batteries, too.
SOLUTION 4: Flatten Renewable Supply With Storage
We’ll need to flatten the peaks of demand and troughs of supply with storage. We’ll need quite a bit of short term storage, even more medium-term storage (on the order of hours), and we might also need some longer-term storage (up to a day or two).
How much? Depends how aggressive we are on the other solutions, and how cheaply we can make storage.
The world’s minds are bent on the problem of storage, and while there are different limits to each storage technology, there is nothing standing in our way of solving the storage problem- making storage cheaper, more reliable, and less dependent on either geography, special materials, or burning stuff either.
What storage options?
Using existing hydro – by operating hydro as a modulating source rather than steadily as baseload, we can better flatten the more intermittent renewables. Thats not a feasible option for all hydro installations (i.e. run of river, or where reservoir levels must be controlled, or there is no reservoir at the base of the dam), but right now the potential for modulating hydropower is basically untapped- we run the dams flat out most of the time because this power is cheap and green, and the capex is sunk already. Quebec alone apparently has enough water in its upper reservoirs to power Quebec for a year. The potential for Quebec to become a giant battery for a good chunk of North America seems pretty enormous to me.
Li ion batteries for the shortest duration, highest power, highest value grid support services. The Hornsdale battery in Australia has already paid itself off doing just that- the rest of its lifetime is pure gravy for its owners. UPDATE: LFP prismatic cells are $90 retail per kWh, delivered to Canada from China, per our recent order in March of 2024. Guaranteed for 6000 cycles. These batteries return kWh for about 2.5 cents each, plus whatever interest you want to pay yourself on the investment to buy them. Building a pack out of them costs $20 and takes ½ hour. The notion that batteries AREN’T the future of storage is just insanely wrong. And sodium ion has, over the next decade, the potential to make battery storage so trivially cheap that even long distance sea freight may go electric.
Flow batteries: a flow battery is like a fuelcell in that it de-couples its storage from its power generation. More stored energy is just more electrolyte stored in big plastic tanks- it has a cost, but it doesn’t go bad or self discharge. And when the power unit- sized to make and absorb the peak power you need- is damaged or degraded, it can be repaired, unlike a Li ion battery which must be recycled because it is a sealed unit. Flow batteries are useless for transport applications but seem ideal for grid storage- if they can be commercialized, which means if they can be made cheaply enough at scale. That remains to be seen.
Pumped Hydro: geographically limited, but not as much as you might think- see Michael Barnard’s piece in CleanTechnica for details. Not perfect- high capital- but high efficiency and low operating cost.
Compressed Air or Liquid Air Storage: the former is well known, not very efficient, and very much dependent on having giant volumes of storage for the very low energy density storage medium. The latter is unproven at scale as a storage medium. But both appear to be far more efficient than their big putative rival, which is hydrogen.
Heat Storage: or cold storage. If were using heat, or keeping things or people cool, we don’t need to do that instant by instant. We can buffer heat, or cold, easily enough. And by so doing, we can shift when we draw electricity to make heat, or cold. Brine ice storage, molten salts etc. all have a role here.
Fuels: well also need some stored fuels for emergency response. Here, we have week-long periods where a high pressure area sets in, winds stop, and snow covers the solar panels. Well need some stored fuels to handle those periods: biofuels and hydrogen are possibilities, but even if we use fossil fuels for 2 weeks a year, we’ve already won.
SOLUTION 5: Flatten Renewable Supply with Wider Grids
The storage problem gets dramatically easier to solve, the easier it is to move power around from where its made to where its used. Grids are already quite efficient- the US average from plant gate to home meter is about 5% loss, which is basically identical to the loss from well to meter for natural gas (and about 1/3 that for hydrogen by the way).Were already moving power vast distances by means of HVDC lines. Power made in Labrador and northern Quebec’s giant hydro dams is right now powering the eastern US by this means.
SOLUTION 6: Flatten Demand By Smart Demand Management
EV charging is a perfect example of this already, even without a smart grid to control it. Users plug in at night to take advantage of cheap overnight power prices. As long as they are back up to the desired level of charge by 7am, they don’t care when or how fast they take power.
Similarly, we never dry our laundry or run our dishwasher before 7pm in the evening. Time of use pricing has trained us well!
(Update: in the future, you’ll push the button on the dryer and it will say, “Starting at 11:01pm when electricity is cheap. Press the start button again if you really need your clothes to be dry this instant”. Devices will come pre-programmed to help you not use expensive energy)
My local utility also pays me for the right to shut off my air conditioner for 15 minute periods when peak demand is happening. The house doesn’t heat up appreciably in 15 minutes, so frankly I have no idea whether or not they’ve ever done this. If they have, I’ve never noticed. Why wouldn’t you do this with many similar big loads?
There are many other examples of things that can be operated when power is cheap, or available, rather than the instant they’re needed. And many can be interrupted any time power is in short supply, without consequences. Some of them arent really storage per se, just being smarter about WHEN we use energy.
SOLUTION 7: Build Nuclear, if You Can Afford It
We won’t be using this solution in Ontario where I live. (UPDATE: our closeted climate change denialist premier is betting on future small, modular nuclear reactors- four of them to replace the output of a single reactor at Darlington. This is economic nonsense, as the reactors in question are neither small nor meaningful modular, but it suits his political ideology- including pushing real energy solutions far enough into the future to become somebody else’s problem.)
We make 55% or so of our power from nuclear right now. It was a brilliant decision on the part of my parents’ generation, to build huge CANDU plants instead of the only real alternative at the time- more coal burning. The decision literally saved hundreds of thousands of premature deaths. It was also likely the CHEAPER solution, even without trying to figure out how many person-years of saved lives were worth in some kind of macabre accounting exercise.
There have been ZERO deaths in Ontario from nuclear power accidents. There has been no significant radioactive release, except perhaps at the uranium mines. We know where all the waste is- it was not broadcast across the countryside.
But as much as I think there is good evidence that nuclear can generate very safe, very low GHG and toxic emissions power on a steady 24/7 basis, it certainly isn’t cheap power.
Case in point: Darlington is the last nuclear plant built in Ontario. It cost about $14.4 billion to build, on a budget of $4 billion, in the early 1980s. It has four reactors with a total thermal capacity of 4×878 MW, for a total capacity of 3.5 GW of electricity. It has been a very good plant, making power very safely and reliably since it was built. It is currently being refurbished for another 35 yrs of operation (to 2055), at a cost so far of $13 billion. Lots of kWh generated over a very long projected lifetime (75 years!), but not cheap…In 2013, Ontario looked at building a B unit to make Darlington’s twin. The bids came back way too high, and the idea was shelved. No politician in Ontario will touch the construction of a new
full-size CANDU plant, even with somebody else’s bargepole.
(Update: I was wrong about this- see above. We’re apparently going to build four new reactors)
Here, what will happenshould have happened is the truly sensible thing: we’ll run our existing nuclear plants right into the ground- as long as they can be run safely. The first one built, Pickering, goes lights out for good in 2024. Two of the six reactors are shut down already- the other four, about 2 GWe worth, go down in 2024
(Update: we’re considering refurbishing them, likely throwing considerable good money after bad)
And nobody in Ontario knows what well replace it with, except for one thing: it will not be another full size CANDU plant.
(Update: although there’s talk again about building a Darlington B, or more reactors at Bruce, that talk is likely just talk)
If in your society you can build nuclear, and you think that’s a good deal, then you should do it. As long as you will cope with your own nuclear waste, that is.
Don’t hold out hope for the small modular nuclear reactor however. It will not make cheap kWh, period. It is pure #hopium, predicated on a fundamental misunderstanding of engineering economics. I’ll deal with that in a subsequent article (link given above).
SOLUTION 8: insert your solution here (as long as it’s NOT hydrogen or e-fuels!)
SOLUTION 9: Be More Efficient, and Use Less
We had a good party for the past 300 yrs on the stored solar energy the earth put up for us in the form of fossil fuels. But sadly, the party’s over.
We learned some foolish energy use practices in that time, like dragging two tonnes of steel around per person everywhere we go. Well need to un-learn that to some degree. We’ll need to be smarter. We’ll need to move information rather than people whenever that’s practical (COVID taught us that this was far more practical than we imagined!). We’ll need to combine moving our bodies to where we want to go, with our need for physical exercise. And well need to build more public transit, and densify our communities to make that transit a viable option. Thats however a 70+ yr, multi-trillion dollar exercise. Its not going to happen tomorrow.
This also means that we use thermodynamic work as work, not stupidly as if it were heat!
That means we use EVs, not engine-driven vehicles, everywhere that’s feasible.
NOW.
As soon as practical!
Thats basically almost all cars and light trucks, most heavy transport, and part of planes, ships and trains.
The rest?
Biofuels.
They’re cheaper and more effective than hydrogen. They still make toxic emissions, but those matter a lot less when emitted between cities or at 30,000 ft, or mid-ocean, rather than inside densely populated areas.
Make me benevolent dictator and Id ban new sales of non-hybrid ICEs tomorrow. I’d ban new sales of mild hybrids in 2030, and I’d ban fossil fuels for engines by 2035
That, plus carbon taxes, would transition transportation completely.
And no, there are no materials availability nor other impediments to doing that. It’ll just be very expensive- and then as we get better at it, and we finally accept reality, it’ll get cheaper!
Can we scale biofuels enough for the rest? For those applications EVs can’t work for- yet? Yes, I’m convinced we can (2024 update: I remain convinced of this, more solidly than ever). But not without carbon taxes. Biofuels are much more expensive than fossils. They’re however cheaper than hydrogen, as well as being more effective than hydrogen (more practical). And that means, biofuels are ALSO cheaper than any so-called e-fuel, all of which are actually hydrogen-derived fuels.
Don’t believe me? Don’t like the idea of biofuels? No problem- except YOUR problem just got far harder and more expensive to solve than mine!
You may not realize it, but we already are supplying about 10% of our gasoline in Canada and the US in the form of ethanol, and a fraction of our diesel as well. It is driven stupidly by mandates rather than by carbon taxes, so the fuels aren’t as fossil GHG -efficient as they could be. But the capacity to make vastly more from cellulosic stocks (at much higher cost) is absolutely there. And those stocks can be combined WITH green hydrogen, if that ever gets cheap enough- to make even more.
Note that the whole food versus fuel thing is real, but the real problem with agriculture isn’t biofuels production, it’s an uncontrolled case of parasitism. You pay 9 out of every 10 dollars for some foodstuffs, to people OTHER than the farmer. That’s a travesty bordering on criminal in my opinion. If you’re concerned about food prices, THAT is the problem to focus on solving!
This also means using heat pumps for comfort heating. They’re expensive, but only because gas is so cheap when you get to dump fossil CO2 to the atmosphere nearly for free.
Home heating is much harder to replace with electricity than it is to electrify transport. It will take longer, and it will take more than carbon taxes to make it happen. We should start with steeper requirements on new construction for energy efficiency. Weve been ramping these up since the 1st energy crisis in 1973 and thats a good thing, but we can go MUCH farther if we put our minds to it.
SOLUTION 10: Replace Non-Fuels Uses of Fossils
One of the dividends we’ll get when we stop burning fossils is that well have lots of fossil petroleum and natural gas for uses other than burning. We can make chemicals and plastics from fossils without burning fossils in the process, or in some cases, with a little carbon sequestration being necessary. Not a single new invention is required to do that- just a steep enough tax on carbon to make it pay.
One of the most important transitions is to stop making hydrogen from fossils. Thats how we make 98.7% of hydrogen right now (Update: it’s still the same- we basically are NOT transitioning away from black hydrogen toward green hydrogen in any meaningful way), and solving that problem is literally existential for humankind if we really do want to kick the fossil-burning monkey off our backs.
We literally depend on that BLACK hydrogen, made from fossils without carbon capture, to continue eating in the post fossil world. Most of our food calories and those of our food animals are dependent on nitrogen fertilizers made from ammonia made using black hydrogen. We have to kick that habit, and we also need to be smarter about how we use nitrogen fertilizers too. N2O is a durable and extremely potent GHG, and it is made any time we over-dose our soils with artificial nitrogen. Just transitioning about 1/2 of the 120 megatonnes of H2 we use in the world yearly right now- in the form of H2 and of H2-containing syngas- to non-emitting sources, is a giant task. We’ll be at that for decades even if we work at it as hard as we possibly can. And we literally haven’t even started yet.
Needless to say, I therefore do not see us using surplus green hydrogen to solve our GHG emission problems. Thats just a #hopium hallucination you’re being sold by people who would profit from you believing in it.
What About CCS? Or Direct Air Capture (DAC)?
Carbon capture and storage is likely going to be necessary to some degree. But right now, its as much a fantasy as green hydrogen. Carbon taxes in the world are too low to pay for it.
Can you imagine an industry the size of the current fossil fuel industry, moving TWICE as much mass but in the opposite direction, paid for entirely by carbon taxes?
Sorry, I can’t!
So I see carbon capture and storage as necessary for things like cement manufacture and perhaps a few other things- but NOT for energy production. We should really endeavor to minimize how much of it we use though, as the risk of us suddenly having a giant CO2 eruption somewhere seems quite real.
What we should not be confused by is enhanced oil recovery. Thats a scam being run by the fossil fuel industry, who is trying to get carbon credits for something they do for their own profit. When the oil extracted is burned, we end up with MORE CO2 in the atmosphere, not less. Giving credits to oil and gas companies for EOR is madness. Its the kind of bad public policy that we can expect going forward though, unless were very vigilant.
Lastly, the idea of direct air capture of CO2- moving 1600 tonnes of air through giant absorbers to recover each tonne of CO2- is just something that should be rejected out of hand until AFTER were done burning fossils for good. You patch the hole in the hull first, before you try to bail the boat!
You’ll hear that endlessly in my posts and comments here on LinkedIn. But here are a few:
small modular nuclear reactors (SMNRs)hydrogen for heating or transport (green H2 to replace black H2 is critical though!
hydrogen for high temperature heating- there’s nothing in heating that H2 can do that electricity cant do BETTER, unless you’re looking at avoiding the retrofitting of existing fired equipment. Then it’ll be cheaper to do the retrofit and electricity STILL wins
making ammonia to move green hydrogen- use the green ammonia to replace BLACK ammonia instead!
making e-fuels (from hydrogen) to keep using our beloved ICE vehicles. Biofuels make far more sense for that, at lower cost- those that EVs cant replace yet that is!
waiting for fusion: the fusion reactor 93 million miles up in the sky suffices. The time into the future that fusion power will be a practical alternative is one of the constants of the universe
waiting for whatever other fancy deus-ex-machina technological solution you imagine is coming- because we have all the solutions we need to do this NOW
There are innumerable other dumb things that people are going to convince us to try to do. While its very important to separate the truly impossible from the merely difficult or uneconomic, it is not sensible to take the “all of the above” approach. We can and must work from what we know of the limits of each technology, to select which ones have the most promise and pursue those. And we can’t delay! Nor can we dream that the transition is at all possible without solution #1- carbon taxes.
In Conclusion
I intend to edit this as I learn and hence change my mind. Convince me where I’ve gone wrong! I know I have. Thats the fun of it- acknowledging what were trying to do and then working together to solve it, we can accomplish incredible things! But only if we don’t hold our own ideas as too precious to be changed by better ones.
We’ve had 30 solid year- my entire career, so far- to tackle this problem, and we haven’t. Why not? Because we’ve been wallowing in grief instead. Denial and bargaining- they’re stages of grief. Thats where our energy has gone, not into solutions. As natural as grief is, and as unhealthy as it is to suppress it, at a certain point we all must move on. Take off the black clothes and the arm band, put on the workboots, fire up the simulator, dust off the calculator, put on the lab coat, mark an X beside the right candidate’s name in every election.
Let’s get on with it!
Disclaimer: this article was written by a human, and humans are known to get things wrong from time to time. Explain to me how I’ve gotten this wrong, with good references, and I’ll be happy to correct my work.
If you’re dissatisfied with the article merely because I’ve taken a dump on your pet idea, feel free to contact my employer, Spitfire Research Inc., who will be quite happy to tell you to piss off and write your own article.
Join in the discussion on LinkedIn, as I don’t have comments enabled here- too much spam to make it worthwhile.
First, why do I care what the answer is? And why should you care? A little history may help you understand.
My son Jacob and I took on a project a little over three years ago, to convert my 1975 Triumph Spitfire roadster into a fully electric vehicle, which we call the E-Fire. The project flowed from my personal and professional interests in the transition to renewable energy sources and in reducing the environmental impact of global energy consumption. It was also spurred on by my purchase of our first Prius in 2008. I have driven nothing but Priuses since: I’m fascinated by the seamless way that Toyota managed to integrate the EV drivetrain with the Atkinson cycle gasoline engine. The vehicle not only has exceptional fuel economy, but toxic emissions are also greatly reduced.
(We won’t be needing THIS any more! 80 pounds of gasoline with a flip-top lid, separated from the passenger compartment by a 1/8″ thick sheet of pressboard covered with vinyl, always had me a little worried…)
(Jacob wiring the front battery pack: 22 LiFePO4 batteries. Another ten went where the gas tank used to be. The result is 100 km (60 miles) reliable range on a charge, without leaving the cells at a damagingly low depth of discharge)
The E-Fire project was a great opportunity for me to integrate these interests and to work together with my son at an age where he could be both a learner and a real helper too. That said, I would have considered the project a failure if I didn’t also produce a car which was useful for my commute, at a cost (ignoring our labour of course!) far less than that of the cheapest EV available to me at the time, a Gen 1 Nissan Leaf.
(If you’re going to put up with a 75 mile round-trip commute daily in the Toronto-Hamilton region’s notoriously disgusting traffic, you might as well do it in something fun!)
The result is spectacular: a car which is an absolute blast to drive, and which turns heads, but which has also reduced my commuting energy consumption by 80% and greenhouse gas emissions by 97%. That result is due to both the efficiency of the EV drivetrain and to Ontario’s unbelievable 40 g CO2/kWh electrical grid. After over 11,000 miles of driving, my face is still sore from the “EV grin”. The instant, quiet torque of an electric motor is quite intoxicating!
The project of course also fed into my interests in the feasibility and limits of both renewable generation and energy efficiency improvement measures by which we could meet the incredible challenge of transitioning away from fossil fuels- something which an honest evaluation of the science on the topic makes quite clear to be an absolute necessity. A lot of my LinkedIn commentary is now tied to issues related to efficiency, renewable generation and the threat of global warming, because frankly I see a tremendous amount of uninformed rubbish being spewed daily, in the form of unfair criticism or denial, unsubstantiated claims, crazy predictions or hype related to particular technologies. What often passes for “science journalism” in the Internet era just makes my blood boil: how can we expect non-technical people, which most of our voters and political leaders are, to make reasonable decisions on technical matters if we keep feeding them this garbage?
Case in point is the subject of this article: just exactly how much electricity does it take to refine a gallon of gasoline?
Here’s the quote from Elon Musk, in an interview related to the release of the movie “Revenge of the Electric Car”, which I found here:
Elon:“Exactly. Chris has a nice way of saying it which is, you have enough electricity to power all the cars in the country if you stop refining gasoline. You take an average of 5 kilowatt hours to refine gasoline, something like the Model S can go 20 miles on 5 kilowatt hours. You basically have the energy needed to power electric vehicles if you stop refining.”
Ding! My “hype detector” went off on that one, big time! This had to be an exaggeration. If it were true, it would make no economic sense at current retail gasoline prices, for one thing. But Elon Musk is a smart guy, so there’s no doubt a grain of truth in it, as there is in most myths. It was time for a little digging to find the source of the error.
I sat down and read the GM/Argonne National Laboratories well to tank and well to wheels studies to figure this out, as part of an effort to do accurate calculations for my own converted EV’s energy and GHG performance.
The GM/ANL study and the resulting GREET model are very complex, as you would expect given that oil refineries produce a lot of different fuels-gasoline, diesel and jet fuel, home heating oil and bunker fuel for ships, propane etc. But refineries produce a host of other products, and also internally recycle a lot of material and energy, often sharing energy and materials across the fence with numerous petrochemical plants which don’t even count as part of the refinery itself, and with the greater electrical grid.
The end result of a very careful and well-documented analysis via the GREET model which takes all of this complexity into account, is that from well to gas tank, gasoline is about 81 to 83% source energy efficient. The figures from the US average in 2001 were 98% for production/recovery, 84.5% for refining, 98.41% for distribution/transport to and from the refinery, and over 99.8% for storage. All the figures except the last one are from the GE/ANL well to tank study (2001) and subsequent well to wheels study, except the last one which is from Environment Canada. The figure compares almost exactly with the more recent EU JRC well to tank study (2014) which gives a comparable figure of about 82%. Put simply, this means that 118 J of energy in crude oil is used to produce 100 J of energy in the form of gasoline. 18 J is “lost” in the process.
As an engineer, such a comparison leaves me a bit cold. Even though heat and chemical energy and thermodynamic work and electrical energy all have the same units (Joules), that does not mean these forms of energy are all equivalent! The gods of thermodynamics take their tithe any time energy changes form.
OK, let’s look at Elon’s claim on its face: 5 kWh/US gallon is about 5/35.3 kWh or about 14% of the lower heating value (LHV) of a gallon of gasoline- but only if you were to convert the LHV (heat units) into electrical energy (kWh) at 100% efficiency. Ding! There’s the error! Of course aside from small home or jobsite generators, nobody burns gasoline to make electricity (regrettably there is still a lot of diesel burned though…). In general, simple fuel-burning power plants are on the order of 30% efficient based on the lower heating value (LHV) of the fuel. A modern gas-fired, combined cycle power plant can now reach about 60% efficiency, but that’s really not a fair comparison here.
Looking at the biggest energy sink in the gasoline production chain, which is refining at roughly 15% of the source energy, it’s important to know that most of the energy used in the refinery isn’t electricity. Fuel gas is used either directly in fired equipment or indirectly to produce steam, and it represents most of the source energy loss. A lot of that fuel gas in most refineries consists of byproduct streams from within the refinery itself, so it really does originate from the source, i.e. from crude oil itself.
Converting 15% of the chemical energy in a gallon of gasoline to electrical kWh at 100% efficiency is disingenuous because doing so in reality is impossible. On average, only about 15% of the energy used in a refinery is used in the form of electricity. Some refineries are electrical importers, and some are exporters from their cogen facilities, so only the average across a country or region is worth considering.
For a fair evaluation of Elon’s claim, the 15% of the 15% of the source (crude oil) energy used in the refinery in the form of electricity should be converted from source energy (fuel gas) at closer to 30% efficiency. A barrel of oil equivalent has a LHV of about 35.6 kWh/gal which is very close to the 35.3 kWh/gal LHV figure for a typical gasoline. So 15% x 15% x 35.6 kWh/gal is about 0.8 kWh/gallon of actual electrical energy use. Converted back to equivalent fuel gas used to make that electricity at 30% efficiency, you end up with an overall real well to tank efficiency for gasoline of about 80%, i.e. 2-3% worse than the figure which treats electric energy and fuel LHV as if they were equivalent. The GHG emissions figures in GREET work out to roughly the same result when you back-calculate.
My converted EV could drive about 3.2 miles at 250 Wh/mile on the electricity saved for every gallon of gasoline it didn’t use (that 250 Wh/mile figure is what my car averages, taking into account the efficiency of the charger and battery). Pre conversion, my Spitfire got about 29 miles to the US gallon if driven conservatively, so we’d make it roughly 1/10th as far. Elon’s Model S is a much heavier and larger car, so it consumes more like 400 Wh/mile and would only travel about 2 miles on that energy. Elon’s estimate is therefore out by an order of magnitude, and my “hype detector” was proven to be reasonably well calibrated.
We could do the more ridiculous comparison, taking the overall 20% of the source crude energy lost between well and tank, converting it all back to kWh at say 30% efficiency. That yields 20% x 30% x 35.6 kWh/gallon = 2.1 kWh, or enough electricity to take Elon’s model S a whopping 5.2 miles. Even on this ridiculous basis, Elon’s estimate is still out by a factor of about four.
Clearly, the amount of electricity used in refining and distributing gasoline is not insignificant, but nowhere nearly as high as Mr. Musk claimed. We’re going to have to find renewable sources of electricity if we want to convert all our gasoline cars to battery EVs- much less all the diesel cars, aircraft and ships dependent on crude oil. And more importantly, we have to remember that even if we decide tomorrow that fossil gasoline and diesel, jet and bunker fuel are no longer needed in any quantity (and I guarantee you that we won’t do that tomorrow, or in two decades either!), we would still be running crude oil refineries, adjusting the refinery processes to make a different suite of products. We’ll need to do that to produce the host of other materials and products that are every bit as necessary to modern life as electricity, but which are far harder to make from renewable sources.
I’ll leave you with the measured and calculated energetic and environmental performance of my E-Fire versus itself prior to conversion, and versus my most efficient vehicle- my Prius C hybrid. The results should be crystal clear- in a region like Ontario with a good grid, EVs are an environmental godsend.
Battery EVs are a tremendous technology- one that will greatly help us toward a future which allows us to enjoy most if not all of the benefits we’ve derived from fossil energy, but without the GHG consequences. They will allow us to retain the freedom of individual transport, without discharging toxic emissions directly into the breathing zone of passersby. And the efficiency of the EV drivetrain and lithium-ion battery combination mean that we won’t have to build out as much expensive renewable infrastructure as we would if we were going to rely on other, less efficient renewable fuels such as biofuels or hydrogen- fuels which require more lossy steps of chemical or energy conversion. EVs don’t need hype or exaggerated claims to make them out to be more than they are: they can definitely stand on their own merits.
Is the image I’ve used, and credited above, a fair representation of our future? Hydrogen proponents, particularly those who want to sell us on the superiority of hydrogen as a transport fuel for fuelcell electric vehicles, would like us to believe it. But what would it take to make such a dream- the generation of hydrogen from renewable electricity, a reality?
How Much Hydrogen Do We Use?
Hydrogen production figures for the world aren’t easy to find. Most of the world’s hydrogen isn’t made as a product and sold. Rather, because hydrogen is so low in density- even as a liquid it’s only 71 kg/m3, and as a gas at 10,000 psig it’s only around 42 kg/m3 – it’s quite the devil to transport. Accordingly, major hydrogen users either build their own hydrogen plant, or build their own facilities next door to a major hydrogen plant that already exists. That makes accounting for H2 production rather more difficult than keeping track of how much gasoline or diesel fuel is used.
The best figures I could find for the breakdown of hydrogen sources at present was quite dated- from the year 2000. Here’s how world hydrogen production broke down in 2000:
Total: 500 billion standard m3/yr- roughly 42,000 kT/yr
48% from natural gas
30% from “oil”, generally meaning internal use in oil/petrochemical refineries
Of that 4% made by electrolysis, a chunk of it is hydrogen made as a by-product in chlor-alkali manufacture, some of which is used for energy, some of which is used for HCl production. So the world’s on-purpose hydrogen electrolyzer capacity in 2000 was quite a bit less than 4% of world hydrogen production. All the rest is made from fossils, and resulted in fossil CO2 emissions to the atmosphere.
To a first approximation, let’s consider the 4% made as a byproduct of chlor-alkali to be made with grid average electricity- which in 2018 was about 33% nonfossil/nonemitting. That puts total world hydrogen production at 96 + 2/3(4) = about 98.7% fossil, without carbon capture. The world’s chlor-alkali plants are likely a little greener than the average grid though, given that these energy-intensive plants, and aluminum smelters too, are often paired with hydro dams. So that figure should be used with caution- though it’s roughly correct.
A more up-to-date figure was provided from this reference: (thanks Ameya Joshi!)
(which is quite an optimistic article about a future “hydrogen economy” and how it could be achieved)
This reference from the Hydrogen Council estimated world H2 production in 2017 to be about 55,000 kT per year- a 30% increase from those 2000 figures. However, since the reference doesn’t give an updated source breakdown of that hydrogen production (that I could easily find, at least!), let’s just set it aside for the moment- knowing the job we have to do just got 30% harder over the past 2 decades or so.
UPDATE: This report from IRENA has more recent and fairly solid data from IEA:
It includes this figure, which shows hydrogen uses both as the pure gas and in various industrial processes- and these figures are MUCH higher than those in the previous two:
Today, around 120 million tonnes of hydrogen are produced each year, of which two-thirds is pure hydrogen and one-third is in mixture with other gases. This equals 14.4 exajoules (EJ), about 4% of global final energy and non-energy use, according to International Energy Agency (IEA) statistics. Around 95% of all hydrogen is generated from natural gas and coal. Around 5% is generated as a by-product from chlorine production through electrolysis. In the iron and steel industry, coke oven gas also contains a high hydrogen share, some of which is recovered. Currently there is no significant hydrogen production from renewable sources. However, this may change soon.
The IRENA report confirms the ~ 5% figure for byproduct hydrogen from chlor-alkali, and also confirms that almost no hydrogen is currently made from renewable resources. But the amounts of hydrogen used are much, much higher- 120,000 kT (120 megatonnes) per year if you include the hydrogen in syngas used to make methanol, hydrogen used in refineries etc.
Note that in 2019, virtually no hydrogen was used to power vehicles. About 40 MT of H2 was used in refineries- there isn’t data as to how much of that was produced FROM refinery waste streams. At least 1/4 of that, or 10 MT, would still be required even if we swore off the burning of fossil fuels entirely, because we would still need H2 to desulphurize petroleum used in making chemicals, plastics etc.- things we’ll still use petroleum for even once we’ve (hopefully) stopped wasting it for its lowest value use to humankind- as a fuel.
Let’s do a simple calculation to put the current hydrogen use in perspective. Let’s take the 40,000 kT of non-fossil pure H2 production in 2000 (i.e. 1/3 of the total reported by IRENA for 2019), and assume we wanted to make that today using a 70% efficient PEM electrolyzer- 70% on a lower heating value basis i.e. relative to 33 kWh/kg of useful energy in hydrogen. Relative to the higher heating value which includes the heat of condensation of the product water, which is more commonly used to make electrolyzer efficiencies sound good, that’s over 83% efficiency- more or less the system efficiency state of the art at present. Cheaper alkaline electrolyzers run about 55% efficient on an LHV basis, for the whole system, based on quotations I’ve received for pilot plant projects. So: taking a 70% LHV efficiency, we’d need at least 47 kWh of electricity fed to make a kg of hydrogen. Storage? That’s extra- storage at 700 bar, common for transport applications, takes at least another 10%. Let’s ignore storage, and grid losses, for the moment just to keep things simple:
40,000 kT/yr H2 x 47 kWh/kg with unit conversions works out to about 1880 TWh/yr.
For reference, the 2016 worldwide non-hydro renewable electricity production was about 2000 TWh (per the IEA, 2018- 8% of world production of 24,973 TWh).
If we devoted 100% of the solar panels, wind farms and geothermal generators which existed in 2016, to producing nothing but hydrogen- and we had the hydrogen electrolyzer capacity to do that- we could have made the amount of hydrogen we were using in the world in 2000 as pure hydrogen, with a tiny bit to spare- not quite enough to store the resulting hydrogen as a high pressure gas.
We’d only manage to make 1/3 of the total amount of hydrogen we used in 2019. That’s using all the wind and solar we generated in 2016.
To make 40,000 kT/yr of H2 would take a continuous 24/7 electrolyzer capacity of about 214 GW. However, renewables such as wind and solar are intermittent. Taking an availability factor of say 33% as an average of wind and solar, that’s around 650 GW of electrolyzers required to replace the fossil hydrogen we used in the year 2000. For reference a 1.5 MW PEM electrolyzer sold by Hydrogenics fits inside a standard 40 foot shipping container. So we’d need 434,000 shipping containers worth of electrolyzers, to a first guess, to replace the fossil pure H2 production in the year 2000. (Thanks to Dave Smith for finding my error- I’d missed correcting for 24hrs/d in my previous edit!)
We can certainly quibble about some of my assumptions- these are low precision estimates for sure. Someday the electrolyzer efficiency might get to 80%, and maybe the availability of renewables will increase to 45% if we build more offshore wind and less solar. But the conclusion is still the same: just replacing the H2 we’re making from fossils – much less ALSO replacing gasoline and/or diesel with hydrogen – is a positively staggering task.
Not impossible– but very, very difficult to imagine.
And that’s a disaster really, because if we want to curtail fossil CO2 emissions we’ll need to make ammonia, urea and nitrate from renewable rather than fossil hydrogen – the alternative is to give up eating, as the mass agriculture which actually feeds the human and food animal population is very dependent on these sources of nitrogen fertilizer. Ammonia and its derivatives are a huge user of (fossil) hydrogen and are responsible for something around 2% of global fossil GHG emissions right now. Nowhere nearly as bad as transport, or even electricity generation from fossils today- but still a very substantial problem.
This Dutch article, which Google Translate does a pretty good job of making intelligible in English, does a very thorough job of looking at the economics of hydrogen production from renewable electricity as a way to store the value of renewable electricity which might otherwise be curtailed. To paraphrase, the author says, “I can’t make this look beautiful”…
Sure we can- we’re doing it now. But if we want to make hydrogen from fossils without emitting fossil GHGs to the atmosphere, not only do we have to be very careful about methane leakage (most H2 is made from fossil methane), we also have to consider what to do with that CO2. There is, in theory, sufficient deep saline aquifer capacity to stuff all that CO2 into, and about 2/3 of the CO2 produced by a steam methane reformer is at pressure and hence fairly easy to separate out for sequestration. But of course stuffing CO2 into the subsurface takes two things in abundance: energy, and MONEY for high pressure compressors and injection wells and pipelines.
Right now the big use for CO2 collected from burning fossils is as a way to get more fossils out of the ground by means of enhanced oil recovery (EOR). Is that helping? It is, when it offsets the mining of natural CO2 for the same purpose- but it does ultimately result in even more fossil CO2 in the atmosphere.
There’s another way: it is possible by a variety of means to convert methane not to CO2 and H2, but rather to H2 and carbon. One of my company’s customers, Monolith Materials, is doing this right now, and it’s a spectacularly good idea as a way to make carbon black- useful in all sorts of applications- while also making hydrogen. Their website has lovely pictures of their pilot plant which I had a hand in designing and building:
Of course Monolith would freely admit that if they had to bury their carbon black instead of selling it as their primary product, they could never make a business out of selling just the resulting fossil CO2 emission-free hydrogen.
Other firms are planning to do the same with graphite being the desired product.
A little math here is very instructive. Let’s say 60 megatonnes per year of H2 are still needed after we stop fossil burning deliberately, i.e. 1/2 of how much we use today. If we were to find a magical way to do endothermic pyrolysis of methane without spending ANY ENERGY- i.e. this is impossibly optimistic- then we’d need to use 60 *16/4 = 240 megatonnes of methane and produce 180 megatonnes of carbon per year. For reference, the world markets for carbon black and graphite are 14 and 1.5 megatonnes per year total. We’d be making, and burying at cost, rather than using, an awful lot of artificial coal if that was our intended way to make hydrogen!
All in all, methane pyrolysis, done right, is a nice but very PARTIAL solution- one which might make money making a product with the production of nonemitting hydrogen being “gravy”. But it’s not a scalable solution to be a significant source of nonemitting H2 relative to how much we use now, or might use in the future once we stop burning fossils as fuels- much less for new inefficient uses.
What About Biomass?
There are other good ideas out there. We can make some hydrogen by gasifying biomass, or by reforming methane produced from waste biomass by anaerobic digestion. It is a little challenging and fairly lossy, as H2 for fuelcells needs to be very pure- less than 10 ppm total in CO and CO2, which is a stretch when you’re starting with a biogas stream which is 500,000 ppm CO2. Using biomass will help reduce the challenge of de-fossilizing H2 production. In fact, reforming biogas is cheaper right now than electrolyzers as a source of renewable hydrogen, and hence that is apparently the major source currently of the 1/3 of hydrogen for use in fuelcell vehicle refuelling in California by mandate. The other 2/3 of FCEV refuelling H2 is made from fossils, and is much cheaper- even though California has a modest carbon pricing scheme. Retail, California H2 is $15/kg – $75 to drive a Toyota Mirai 320 miles. Not a cheap fuel…
Beware the lure of biomass however. Read www.withouthotair.com to see just how much energy we use, and how much we could make from biomass even if economics were no option. Biomass-derived fuels are again, a nice but very partial solution if done right, and a source of environmental and social harm if done wrong. And when they’re used, using them directly as fuels makes more sense than converting part of their energy to another fuel unless that is absolutely necessary. One place this IS necessary is to fuel jet aircraft. Hydrogen is possible for that purpose, but is a very impractical option for a mode of transport that really cares about energy density per unit weight AND volume because it has to push that volume through the air at high speed.
Beware the Lure of Renewable Hydrogen
I’ll leave you with this caution: these facts aren’t, or shouldn’t be, unknown to even the most ardent fuelcell vehicle supporter. They tend to heap on the criticism of battery electric vehicles because we still make a lot of our electricity worldwide from fossils too. However, the proportion of electricity made by low GHG emission sources is positively HUGE compared to the proportion of hydrogen production from non-emitting resources right now. And because battery electric vehicles are over 3x as energy efficient as FCEVs, using that electricity directly rather than indirectly via the lossy hydrogen middleman will mean that the challenge of building out renewable generation capacity will be 1/3 as great if we go this route for cars and light trucks- where batteries are a fully feasible alternative to hydrogen.
Consider the possibility that something else is going on: since hydrogen right now is overwhelmingly made from fossils, is it likely that fuelcell vehicles would actually be fuelled with renewable hydrogen? Or is this a “bait and switch” scam to sell you fossil fuels in another form? Some H2 advocates are more honest about this than others.
My articles about hydrogen fuelcell vehicles, and why I think they’re a dead end for cars and light trucks:
Disclaimer: everything in this article is my own opinion. I provide references where possible, as links so they’re easy to check. But I’m human, and hence prone to error. I encourage anyone who can show where my calculations are incorrect, with references, to let me know and I’ll edit my article promptly.
Few in our society realize just how dependent we all are on a poison gas.
Ammonia has literally permitted about half the humans on earth today to exist at all. The vast majority of our food calories, and especially those of our food animals, are totally dependent on ammonia as the source of nitrogen fertilizer. And, so too, our major liquid biofuels (ethanol, biodiesel) are also quite dependent on ammonia.
How do we make ammonia? We make it by reacting hydrogen and nitrogen at high temperature and pressure over an catalyst, by a process that has been in massive use for over 100 years.
Nitrogen is very unreactive, so we need high temperatures and pressures- and a good catalyst- to make it react with hydrogen at a reasonable rate. However, at high temperatures, ammonia wants to “crack” and fall apart to N2 and H2 again, so the yield is low. Fritz Haber discovered that we could use Le Chatelier’s principle to drive the reaction to the ammonia by condensing out the ammonia as fast as it is produced to drive the equilibrium reaction to the desired product, though his osmium catalyst (a Pt group metal) was rare and expensive. Carl Bosch took Haber’s process and scaled it up to 20 tonnes per day by 1913, with the help of Alwin Mittasch who discovered the much cheaper and more effective iron catalyst that made the process truly practical. And for these discoveries, both Haber and Bosch received Nobel prizes.
Here, the ironies become rather deep and delicious. And those who are here for the technical stuff and don’t care about history (and hence don’t mind the risk of repeating it), may wish to skip the next section of this paper.
(History haters start skipping here…)
The first application of the Haber Bosch process was not to make fertilizers to end hunger for millions, but to permit Germany to avoid the British embargo on the world’s prior primary supply of nitrogen compounds: guano (bird dung) found in islands off South America. It is said that the British imagined that Germany would run out of munitions in a few short weeks, because they effectively controlled the world supply of nitrate from which explosives were made. Germany’s mastery of the Haber Bosch process permitted them to make all the nitrate they wanted from ammonia, made from nitrogen from the atmosphere and hydrogen made from coal. Not only therefore did Haber and Bosch therefore permit World War I to continue to its unimaginably bloody conclusion, but Haber added to this by being an active participant in Germany’s chemical weapons program during the war, standing by as a observer as chlorine was first used to deadly effect. His wife, also a chemist, committed suicide in shame over her husband’s actions.
Haber, being Jewish, found himself to be the wrong flavour when the Nazis came to power- his history as a putative German patriot and Nobel laureate was insufficient to insulate him.
As I already mentioned, Haber was awarded a Nobel prize, despite howls of protest about his wartime activities at the time- the award of course being made from Alfred Nobel’s estate. Nobel, whose invention of dynamite tamed the nitroglycerine that had accidentally killed his own younger brother and turned it into a tremendously beneficial explosive for construction and mining, bequeathed the Nobel Prize awards after reading a premature obituary titled “La marchand de la mort est mort” (the merchant of death, is dead). His own history as a munitions manufacturer was something he couldn’t live down, and the awards were putatively an attempt to put a better spin on his legacy.
(History haters can start reading again…)
I say the ironies are deep and delicious here, because the same ammonia that made explosives that killed millions during WWI, ultimately became- no joke- the very basis of human civilization. Per Vaclav Smil, humans are as big a part of the nitrogen cycle as nature, making as many tonnes per year of nitrogen compounds now as nature does via lightning and nitrogen-fixing plants and other
Smil estimated that if pre-ammonia agricultural yields still prevailed per the year 1900, we’d need four times as much arable land under till as we did in 2010 to feed our population at that time. Admittedly, other fertilizers (K, P), pesticides, yield-increasing crop strains and other improvements in agricultural technology also had a big part to play in that- but kid yourself not, human civilization is founded on ammonia and ammonia-derived nitrate and urea. Not only is about 50% of the nitrogen in the proteins in our bodies a result of the Haber-Bosch process, ammonia has been called the “detonator of the population explosion”: recall that world population was 1.6 billion in 1900, and had risen to 7.7 billion by 2018
Ammonia production alone is responsible for approximately 3-5% of world natural gas use, all to make hydrogen. It represents 1-2% of world primary energy use (and yeah, I hate primary energy as a measure, but in this case, it does provide some perspective).
In greenhouse gas emissions terms, things are even worse than you’d imagine. When nitrogen-containing fertilizers (including natural ones) are used, nitrous oxide (N2O) is released from the soil into the atmosphere. N2O is a surprisingly persistent and extremely powerful greenhouse gas. So we get a triple whammy from our current ammonia addiction:
1) we get fossil methane emissions from producing natural gas (86x CO2 as a GHG on the 20 yr time horizon, despite a short atmospheric half-life of about 7 yrs)
2) we get CO2 emissions from fossil fuel reforming to make hydrogen from which to make ammonia and
3) we get N2O emissions from excessive N-containing fertilizer use (298x CO2 as a GHG on the 100 yr timescale, with an atmospheric half life of 100+ yrs just like CO2 itself)
Man, we’ve got it bad for this molecule! And yet we really, really like to eat…
Ammonia In A Post-Fossil World
We’re going to need it- huge amounts of it- even once we finally kick the fossil monkey off our backs for good. So where are we going to get it from?
Three possibilities:
From Electrolytic (Green) Hydrogen Made from Renewable Electricity
This is where we’re going, folks. One day. But probably not too soon.
In 2016 we produced about 175 megatonnes of ammonia. At $500/tonne, that’s $87 billion dollars worth. Per year…for one chemical. We actually spent quite a lot more than that, because it costs more to make nitrate and urea from it.
Did I say we liked to eat?
Making it requires about 31 megatonnes of hydrogen just to satisfy stoichiometry. To make that at 55 kWh/kg H2 would have taken about 1700 TWh of electricity- almost all of the ~ 2,000 TWh of wind, solar and geothermal power we made in 2018 per the IEA. In fact, by the time we consider Haber Bosch’s energy efficiency of about 66% (starting with methane not hydrogen), we’d be close enough to say that every wind turbine, solar panel and geothermal facility on earth in 2018 would just about keep us eating- if we used all that energy JUST to make ammonia. It would take more still to make nitrate and urea from it to make it fully useful. (Thanks to @Karan Bagga for finding my error here- I had previously stated 76% which isn’t possible, given that making hydrogen from natural gas is only about 70% LHV efficient best case- getting to ammonia for 66% of the energy in the natural gas is already very impressive efficiency).
Needless to say, we’d be hard pressed to make all that ammonia from electricity. It is absolutely NOT IMPOSSIBLE, and one day we’ll have to do it that way. It will just cost a lot of money and will take up a lot of land and other resources to make that happen. And with an average capacity factors of wind and solar of perhaps 30%, the worst thing would be that we’d have to build about 1 terrawatt’s worth of electrolyzers- plus associated compressors and storage equipment- to make that much hydrogen. That’s 1000 GW worth, or approximately 41,666 of the world’s largest (24 MW) electrolyzers to do that job.
…and at 4-5x the cost of fossil hydrogen right now, green hydrogen isn’t on the table at all. It exists only in marketing bum-fodder and in the imaginations of people selling #hopium to extract money from credulous governments.
From Fossils Using Carbon Capture and Storage
Hydrogen right now is made 98.5% from fossil fuels- without carbon capture. But in return for $150/tonne CO2, we could cut the CO2 emissions of H2 production from natural gas by steam methane reforming (SMR) down by 70% without having to rebuild every SMR on the earth. Going to 100% would be really tough. And that would require us to bury a lot of CO2…at 9 kg of CO2 per kg of H2 and $150/tonne, we’re talking about spending $42 billion per year just to bury the resulting CO2 to make $87 billion worth of ammonia per year. That’d have a fairly significant impact on food prices, assuming we could find a place to dump all that CO2.
Directly From Electricity
A recent paper in Energy and Environmental Science Communications touted itself as a giant new discovery in ammonia production, out of two Australian universities. A new process consisting of two steps: production of NOx from nitrogen using a submerged nonthermal plasma, followed by reduction of NOx back to ammonia by nanowire-catalyzed electrolysis, was touted as the next best thing since sliced bread by the media. Here’s just one of many such breathlessly enthusiastic articles about this new discovery:
Many who are looking for something cool and profitable to do with excess wind and solar energy (and Australia is a hotbed of such work) are looking at ammonia, and hope to do something other than water electrolysis followed by conventional Haber Bosch for a couple reasons:
1) Haber Bosch plants need to be made very large to be profitable, because any commodity chemical like ammonia needs to be made at giant scale to achieve sufficiently low capital intensity- not the best if your resource is distributed in space like wind and solar, as it means you’ll need a big grid to feed a huge energy resource into a sufficiently large plant. It also means a huge capital investment- a $300 million ammonia plant is small in current world scale terms
2) Haber Bosch plants, operating at high temperatures and pressures, need to be operated continuously- 24/7- not just to use their large capital efficiently, but to keep them from destroying themselves due to thermal and pressure cycling. That means storing both hydrogen feedstock AND energy to run them- not the best if your energy source is intermittent, and yet MORE cost
So…people have been looking for alternative ways to make ammonia that don’t involve high temperatures and pressures. Electrochemistry to the rescue!
Sadly, it doesn’t work very well. And this process may well be a big improvement in comparison to the world state of the art, but it’s still terrible- because the world state of the art for direct ammonia synthesis is just that much more terrible.
From the paper, the NOx conversion takes 3.8 kWh per mole of NOx, and the conversion of NOx back to ammonia electrochemically takes another 0.51 kWh per mole. Converting moles to mass, they get 253 kWh of electricity per kg of ammonia. Remember that hydrogen takes only 55 kWh per kg to make from water, and even THAT is too expensive and too energy inefficient- and there are only 3 kg of H2 per 17 kg of ammonia…
How did the media go so far in the ditch on this one? Usually you can’t blame the authors of the technical paper, but in this case, you can. The paper is frankly laden with self-promoting hyperbole- no doubt in an effort to attract more research grant money. But the real problem here is that the authors make a true but deceptive statement on p. 3 of their paper:
“…the theoretical energy limit for NOx generation via non-thermal plasma is 5.56x 10^-2 kWh/mol NOx (in vacuum). This consumption is at least 2.5 times lower than Haber-Bosch process (0.13 to 0.4 kWh/mol NH3)”
0.13 to 0.4 kWh/mol ammonia is about 7.6 to 24 kWh/kg ammonia, quoted for Haber-Bosch but without a reference given in the paper. Not only is that 10.5 to 33 TIMES BETTER than what they managed to achieve with their process, in favour of Haber-Bosch, it doesn’t jibe with what the Australians in the know- from CSIRO- say about ammonia production:
They claim that Haber-Bosch production of ammonia is about 76% energy efficient when produced from methane, or about 1.41 MWhr/tonne ammonia. That’s 1.41 kWh/kg, not 7.6 much less 24 kWh/kg.
Sadly, this hyperbole-laden stuff is the truck and trade of the internet media in relation to ANY innovation related to energy these days. It could easily be a full-time job for someone like me to take apart these articles on a daily basis- but the pay for doing so, really sucks! (In case you’re wondering, nobody pays me to write my articles- I’m writing this one as my Friday night entertainment in lieu of watching Netflix)
Ammonia as a Fuel or Hydrogen Carrier
I’ll leave you not only without solutions for this absolutely existential problem for my children’s future, I’ll sour your day further with a little rant:
Since there is no green ammonia right now, because there is no green hydrogen to make it from, nor any process better than Haber-Bosch to make it by, anyone planning to either a) burn ammonia as a fuel or b) thermally crack ammonia back into hydrogen and nitrogen, is an energetic and environmental vandal.
(The Ammonia Energy Association paper above is far more readable than CSIRO’s paper itself. CSIRO has been a shameless promoter of ammonia-for-energy schemes as it sees them to be in Australia’s national interest. But in my view they should focus on making Australia the world’s largest producer of green ammonia for fertilizer purposes- starting that effort by lobbying for Australia to have carbon taxes, which are the only way anybody will make hydrogen from non-fossil resoures at scale)
Actually, that Ammonia Energy Association distillation of CSIRO’s more technical paper that I linked above is excellent- top notch work. It states clearly the problems with using ammonia as a fuel or especially as a way to make hydrogen and thereby, electricity again.
…and who can blame Air Products? Somebody in Europe told them, with a straight face, that there were going to be millions of hydrogen-fuelled trucks and busses to fuel one day, and that they (Europe) were going to pay through the nose for “green” hydrogen from anywhere they could get it. Cha-ching! Who could resist those cash register bells ringing?
Remember that best case, going from electricity to hydrogen, to storage, to electricity again- bleeding edge, uneconomic best case- is 37% round-trip efficiency. Terrible, compared to anything using a lithium ion battery.
What is it when you get ammonia involved?
11 to 19% And though that’s a range, it’s likely an optimistic one.
Ammonia is a toxic gas, but one which is a liquid at a modest pressure and temperature. Accordingly, crazy people desperate to find ways to move hydrogen in bulk, reach for ammonia. And not only is that just a bad, bad idea from an energetic perspective given the round-trip efficiency, from a terrorism perspective it’s just not even worth thinking of. Imagine a tanker full of gigantic quantities of toxic liquefied gas, parked in a major port, and what a tempting target that would be for some politically or religiously-motivated misanthropes.
Then there’s the fact that making ammonia is exothermic where you have the energy to make it, i.e where you already have excess energy- and cracking ammonia is endothermic, i.e. requiring energy where you don’t have enough. (That’s true of other hydrogen carriers like the methylcyclohexane/toluene organic hydrogen carrier pair too, by the way).
And on top of it, ammonia is a poison to PEM fuelcell catalysts. So you have to waste about 15% of your product hydrogen in the gas purification train just to get rid of the tramp ammonia. Not a problem if you’re burning it in a turbine of course- but then, when you burn ammonia in air, you get NOx- but of course you have plenty of ammonia around to feed the SCR catalyst with to reduce that back to nitrogen.
Not to mention the obvious problem that black ammonia will rush in to fill the market vacuum left by the non-existent green stuff. And using it, is at least (100-76) =24% worse than using the natural gas you could have used instead, plus all the extra cost for the H-B plant. Without carbon capture. That’s what the fossil fuel industry is counting on, by the way- they have no intention of making green hydrogen.
Be watching the ammonia space in the future. Expect more crazy stuff, misinformation, misunderstandings, disinformation and #hopium slinging to cloud the public policy discourse, just like with ammonia’s big brother hydrogen. You know it’s coming- because when people start to realize just how hard, lossy and expensive it is to move hydrogen- the reason that 85% of European hydrogen per IRENA is used right where it’s made- they’ll reach for ammonia out of desperation.
And methanol, too. But that’ll be the subject of a future paper.
December 2021 update:
This interesting paper in Science, again by people at Monash University in Australia (the land most addicted to future ammonia #hopium by far), came up this week:
The real paper in Science is here, but behind a paywall (which p*sses me off- no publicly funded university research publication should EVER be behind a paywall!):
In a nutshell, these people are working not on the direct electrochemical production of ammonia from water and atmospheric nitrogen. They start with H2 which would already need to be made by (at best) 70% electrolysis.
They react the N2 and H2 with one another in a pressurized electrochemical cell containing tetrahydrofuran solvent, LiBF4 as a Li source, and a complex organophosphonium salt as a H+ shuttle. H2 is reduced to H+ at the anode and 3Li+ is reduced to Li3N at the cathode. Li3N then reacts with 3H+ to generate NH3 and 3Li+.
Key here is being able to read and understand claims. “Faradaic” efficiency means how many of the electrons you feed the cell, do the chemistry you want to do. Their Faradaic efficiency is about 69% which sounds good, but there’s no indication in the paper of what other chemistry the remaining 31% of the electrons are doing. It’s likely destructive to the solvent, which means they’re likely going to spend way more replacing THF than they make selling NH3.
The other key is that a Faradaic efficiency is nothing LIKE an electrical energy efficiency. I was unable to even calculate that from the paper’s data and the authors didn’t try either.
Work on low temperature electrochemical alternatives to Haber Bosch will continue and is worth doing. But neither this nor anything else over the past decade is coming anywhere close to releasing us from dependence on H-B for the ammonia that feeds us.
DISCLAIMER: I wrote this myself, based on long experience with chemical engineering and hydrogen, but only a little experience with ammonia. Nobody paid me to write it. No shares are riding on it. If you have a problem with anything I’ve said here, please take it up with me. And if I’ve made a mistake somewhere, in fact or analysis- I’m human, so my apologies in advance. If you point it out to me with a good reference, I promise to revise the paper to correct my error, with my thanks to you for finding it.
If you didn’t get angry- or even if you did- please SHARE my paper so people read it. And go to my profile and read my others, which are all featured there. And share them. Otherwise I’ll go back to watching Netflix…
A number of LinkedIn readers wanted more detail about my conversion of my 1975 Triumph Spitfire to a fully electric vehicle, so I thought I’d put together a LinkedIn version of an article I wrote for my local Toronto Triumph Club magazine, “Ragtop”.
(E-Fire, with its fuel pipeline in the background)
I bought my 1975 Spitfire 1500 in 1988. I was young, foolish, and wanted a car which would give me an opportunity to learn some skills from my father, a retired diesel mechanic and jack of all trades. When I saw those fenders come up with the hood, and the engine sitting there on the frame, I was sold! Not having to work in a cramped engine bay was a major selling point- if only I’d known just how much work that engine would take! I eventually replaced the Leyland engine and transmission with a 2.2L Toyota Celica 20R with a W50 five speed. It never really fit, giving the car an unattractive grin- but it certainly made the car a lot more fun!
The last validation sticker I had on the license plate was from 1996- not coincidentally, the year I started my dreaded 122 km/day commute and moved in with the girl who didn’t like the car…but it wasn’t going to the junkyard quite yet, despite my wife’s pestering. I thought I’d get back to it someday, and then when our son came along, it naturally turned into a future project that the two of us would do together. But what would power it?
By the time my son Jacob was 11 and mature enough to be helpful, I started looking seriously into electric drivetrain technology. With a Prius and a Prius C as our two daily drivers, I was already fascinated by how seamlessly and reliably all the hybrid stuff in those cars “just works”- the driver is unaware of it, and yet it dramatically improves both torque and fuel economy, as well as greatly extending the life of the braking system. Regrettably though, years of storage in a leaky garage, and three years under a tarp during a major renovation of the house, had turned the Spitfire into a Fred Flintstone car.
(before any conversion work was possible, a lot of rust repair was required!)
(parts of the frame/chassis were rusty enough to need reinforcement)
I stumbled across www.diyelectriccar.com and found a whole community of people passionate about converting cars to electric drive. Many Spitfires, TR6s and other classics had already been converted. I also came across Canadian Electric Vehicles, a company on Vancouver Island who sells conversion parts as well as building fully electric low-speed utility vehicles, along with a helping hand to get the projects going. I started putting a parts list together.
I also started doing a little research into the history of electric cars. Apparently, electric cars out-numbered engine-driven cars until about 1912, which not coincidentally is the year after the electric starter was invented. Until about 1900, electrics were also the fastest vehicles on the road.
(Belgian Emile Jenatzy with his electric speed record winner, “La Jamaise Contente” – 66 miles per hour in 1890)
Compared with the horse- 175,000 of them in New York City alone at the turn of the last century, emitting some 1500 tonnes per day of “effluent”, along with the flies and rats they attracted- cars were an environmental godsend. But once the electric starter was invented, ladies and gentlemen no longer needed a chauffeur- and the enormous energy density of gasoline won the day. Every general store became a gas station, and the electric car faded into history.
(The Studebaker Electric)
So, what changed between now and then? Three things: batteries, air pollution, and global warming.
The nickel-metal hydride battery was a good start, but when the lithium-ion battery became popular in portable electronics and power tools in the 1990s, vehicle applications were a natural follow-on. The batteries are extremely efficient, giving back about 90% of the energy they are fed from the power mains. Their practical energy density is almost ten times as great per unit weight as the lead-acid battery- and they can last through thousands of charge/discharge cycles if managed properly.
(Jacob wiring the front battery pack- 22 LiFePO4 180Ah batteries)
(pulling the Toyota 20R engine out of the Spitfire…a tad too big!)
The problem with the gasoline engine car wasn’t the car itself. Rather, it was the same problem encountered by our previous transportation technology, the horse. Horses are great in a rural setting- you can grow their food, and their manure fertilizes the land. But in cities, mass use made the horse an environmental disaster. So too with the internal combustion engine: a few of Rudolph Diesel’s tractors running on peanut oil were one thing, and tens of millions of cars with one person each in them were quite another. Emission controls got rid of most, but not all, of the toxic tailpipe emissions (while also adding complexity and cost and eating horsepower)- but when we discovered that CO2 concentrations in the atmosphere had nearly doubled as a result of our fossil fuel consumption with no end in sight, the world’s climate scientists started sounding the alarm bells.
According to the people who have the training to have an opinion worth considering as truly informed on this topic, there is a risk of severe consequences to the earth’s climate if we don’t do something about fossil fuel emissions to the atmosphere. Nobody knows the exact extent, but the overwhelming majority suggest that the outcome isn’t good. And with billions in India, China, Brazil , Indonesia and elsewhere aspiring to the same mobility and freedom we in the developed world have enjoyed for the past sixty or seventy years, getting a handle on our transportation uses of fossil fuels has to be a high priority.
(body off frame restoration complete- Jacob applying primer)
(the rotten body going back onto the restored frame)
The gasoline engine is a marvellous machine. It used a fuel that was originally a worthless byproduct of kerosene manufacture- a fuel which could be mined rather than needing to be grown. The fuel has an energy density of some 2,400 Wh/kg at a gasoline engine’s average 25% thermodynamic efficiency. That’s still ten times better than the best battery technology available today, in the form of a liquid you can just pour into a tank. But regrettably, that still means that from the crude oil well to the engine shaft, only about 20.5% of the energy taken from the ground ends up as useful work. The rest is waste heat, dumped out via the radiator to later cook you through every hole in your Spitfire’s firewall!
(fabricating new floorpans, so the car would no longer suit Fred Flintstone!)
In comparison, an electric vehicle drivetrain consists of only a few parts: a charger, the batteries, an electronic motor controller and an electric motor. With 6% losses from the electrical grid figured in, and all losses considered, that’s about 75% efficiency from power plant to motor shaft without trying too hard. Even when the source of electricity is a fossil fuel burned in a modern combined-cycle power plant, there is a net energy efficiency benefit to using an electric drivetrain. When you consider that Ontario’s electrical grid is 0% coal and only 9.2% natural gas-fueled on average, the balance coming from nuclear and renewables such as hydro power, the electric vehicle’s efficiency in greenhouse gas emissions terms is rivalled only by electrified public mass transit.
Another benefit of the electric drivetrain is the opportunity for regenerative braking, which can save 10-15% of the energy fed to a car which is normally wasted as heat by the braking system. It does this with zero wear to the braking system, so less frequent brake replacement is another benefit.
So after much study, we settled on an AC electric drivetrain for the Spitfire:
1) a High Performance Electric Vehicle Systems (HPEVS) AC-50 3-phase vehicle induction motor, capable of about 120 ft-lbs of torque from 0-3500 rpm and a peak power of about 77 horsepower
2) a Curtis 1238 AC inverter motor controller capable of 650 A DC forward current and 200 A of regenerative braking
3) a series string of 32 Sinopoly 3.2 V 180 amp-hour lithium iron phosphate batteries, capable of storing about 18.5 kWh of electricity at a nominal 105 volts DC. The batteries should last about 3,000 charge-discharge cycles if kept below 70% depth of discharge and not over-charged
4) an ElCon PFC 2500 watt battery charger and
5) a MiniBMS battery management system, which uses a small alarm board on each battery to detect low and high voltage. A high voltage on any cell stops the charger, and a low voltage sounds an alarm to alert the driver
A few additional parts were required too:
a master contactor, to turn main power on and off to the controller
an emergency disconnect which can be operated by a pull cable from the dashboard
a 35A isolated DC/DC converter, using the main battery pack to charge a small lawn tractor 12V battery which operates the car’s normal 12V systems for lighting, horn, radio etc.
a few relays for useful interlocks, including one that prevents you from driving away with the car plugged in for charging
an inertial switch, which cuts power to the motor when the car is in a collision
an ammeter with shunt- this is the main gauge used when driving the car
an intelligent amp-hour meter, which is the vehicle’s “fuel gauge”
some 2/0 gauge wire, and a 500 A DC rated fuse
a “pot box”- a potentiometer which is pulled by the throttle cable and feeds throttle commands to the controller
a windshield defog heater/blower, which runs off the main battery pack. This is a mandatory requirement to pass a safety inspection in Ontario
The conversion parts were costly- about $16,000 CDN all told- but about $8,000 of that was just for the batteries. If we had the project to do over again, a battery pack from a wrecked Chevy Volt or part of a Nissan Leaf pack would have been a much more economical choice. But if you’re thinking about an electric conversion just to save money on fuel, think again- gasoline is still too cheap to make that a viable proposition.
We chose to keep the transmission and the clutch. While clutchless conversions can be done easily enough, they require a switch to defeat regenerative braking while using the transmission’s synchromesh to change gears (easily done on the Curtis controller). A transmissionless conversion, while possible, is generally a bad idea as it requires you to either give up on “off the line” performance or top speed- you can’t have it all without a very high speed motor. With the transmission, you get BOTH- and the only time you use the clutch is to switch gears. From a stop, you merely step on the accelerator and go- in 1st, 2nd or even in 3rd gear, rather like a golf cart. There is no need to “burn” the clutch at every start, so it should last forever.
(the AC-50 motor (blue/silver) bolted to the CanEV transmission mounting plate (red))
Canadian Electric Vehicles had a transmission mounting plate and hub to fit my Toyota W50 transmission and the AC-50 motor, ensuring a clean and easy installation without worries about misalignment. Installing the motor took about ½ hour from start to finish. Building these from scratch would take considerable effort, but many converters do this to save money.
(trial fit of the front battery box and the control plate where the inverter and charger will be mounted)
We have 22 batteries mounted in a box ahead of the motor, and another ten in a box located where the gas tank was, with 2/0 cables connecting the two packs. That left me with my entire trunk, and took no room from the passenger compartment. The motor, hub and plate (130lbs) and front batteries (280 lbs) weigh only modestly more than the original 1493 cc engine did with radiator, alternator, manifolds, fluids and exhaust etc., and the rear pack tips in at about 30 pounds heavier than the original tank full of gasoline. Although the battery pack puts the weight somewhat forward of the front wheels when compared to the original car, the overall weight and front-rear weight split is fairly similar. Aside from renewing 40 yr old shocks and springs, no suspension modifications were required.
We started the project in the spring of 2014, removing the engine, exhaust, fuel system etc., and then taking the body bucket off the frame. My 12 yr old son was right there with me, learning skills and, by the end of the project, contributing some really helpful work too. By the fall, we had repaired the structurally important rust damage, installed some Miata seats, had the electric drivetrain installed and the car re-wired, and were ready for a test drive for proof of concept.
My first drive of the electrified car- my first drive of the car since 1996- was, dare I say it- electrifying! All that torque available at zero RPM is intoxicating- especially without the exhaust noise or backwash.
It exceeds the performance of the original Spitfire, still handles like it was on rails, and is an absolute joy to drive! I spent October running the car in little loops around our neighbourhood, shaking the bugs out, before spending the winter on the long and painful process of bodywork and painting. I decided to change the colour from the original pimento to topaz orange to make the car harder to miss on the road, as I intended to drive the car to work and back on nice days. My amateur “orange peel” finish goes perfectly with the colour! This is the first, and hopefully the last, car I will ever paint myself!
(if you’re rich, you can still buy body panels for Spitfires. But I had to do mine the hard way, given that batteries had already broken my budget)
(If I had to do bodywork or welding for a living, I’d starve…but I’m still pretty proud of the results. Only one of my many such repairs is looking shabby after 3 years of daily driving spring through fall- so far, so good!)
(the body, painted- after much suffering…)
I’ve had both electricians and electrical engineers review my electrical work and have received nothing but compliments. The car passed mechanical safety inspection with only a few minor issues, and was legally on the road in the spring.
(the E-Fire looks decidedly different under the hood than most Spitfires…leftmost is the Curtis inverter which produces 3 phase AC to drive the motor; middle is my junction box which contains my fuses, interlock relays etc.; right: ElCon PFC2500 charger)
Next to bodywork, finding insurance was the most challenging aspect of the project. Though I had a quote from a major insurer on a full disclosure basis prior to even starting the conversion, they declined to offer coverage when I tried to activate the policy. It seems that our so-called “free market” “competitive” insurance system here in Ontario is not really interested in writing policies for anything out of the ordinary, but some effort negotiating with the insurer’s ombudsman eventually yielded a policy we could both live with- one which permitted me to drive the car as a “real” car rather than a “toy” or “show” car.
In comparison, conversions in BC are insured through the provincial scheme without difficulty. There are many converted cars on Ontario’s roads, and apparently if you find a broker to work with you, coverage is available from a number of insurers (EDIT- not really true! See my subsequent article- finding insurance for an electric conversion in either Ontario or Quebec is next to impossible…but possible!). The irony is, the car is far safer now than it was out of the factory: there is no longer 80 pounds of gasoline separated from the driver and passenger by a 1/8” thick piece of vinyl-covered pressboard, in a tank with a flip-top lid- and the car has a fully redundant braking system which can stop the car even after a total failure of the hydraulic brakes.
Regrettably, there are no tax breaks available for conversion parts or labour, nor are the “green” electric license plates which allow you to drive in the provinces’ HOV lanes available to converted vehicles. But the Ministry of Transportation will permit you to drive the car on the public roads as long as it passes a safety inspection. As a classic there is no requirement to submit to Drive Clean inspections, so no need to re-register the “fuel type”- and there neither an engine computer port nor an exhaust pipe for such an inspection to use, anyway!
(the dash and re-wiring in progress- a wooden dash not only gives a lovely look, it makes re-building a lot easier. The white gauge nestled between the speedo and tach is the ammeter, which measures battery current both forward (during driving) and reverse (during regenerative braking). The delicious irony of turning a Lucas electric-infested British Leyland car into a reliable fully electric vehicle is not lost on me!)
(The E-part of the E-Fire’s dash: a few voltmeters to monitor groups of batteries, DC/DC converter and 12V battery output, the E-Expert Pro Ah gauge (i.e. my fuel gauge) and the ‘Spyglass’ display for the Curtis controller)
So far, the “Triumph E-Fire” as we call it, has been a surprisingly reliable and enjoyable ride. It has a comfortable highway range of about 100 km on a charge. It recharges from my 61 km commute in about 6.5 hours from a normal 120V wall socket- or in half that time from a 240 V electric charging station. We did need to replace the original differential after a failure (hopefully taking the last of the Leyland evil spirits with it!) but I had a spare on hand which seems to be doing fine. So far we have about 14 000 fossil-free miles on the car, saving about 4 900 kg of CO2 emissions to the atmosphere so far. The car emits 3% of the CO2 that it did pre-conversion and is about 79% more energy efficient as well. Surprisingly, it emits about 6% of the CO2 emitted by my Prius C hybrid which gets an impressive 4.5 L/100 km fuel economy.
If you have a great car with a terrible engine, or one you can’t get parts for, an electric conversion may be worth considering. It does take some mechanical and electrical skill, but there’s plenty of help available to make the project a success. It’s a way to breathe the spark of life back into a classic car, while making an environmental statement as well.
I invite you to read my other articles, which are generally listed below. In those articles, I attempt to separate the fact from myth and hype in relation to EVs, hydrogen fuelcell electric vehicles, and electric vehicle battery packs.
UPDATE: Sadly, driving home one July evening in 2018, a large Dodge 2500 pickup truck with dual rear wheels changed lanes into the E-Fire on North America’s busiest section of highway- highway 401 nearing the Yonge express-collectors transfer. While I walked away without a scratch, the E-Fire was destroyed.
The car body was damaged on both sides and the frame twisted- it was not worth restoring. And even sadder, what ensued was a three month battle with my reluctant insurer. The collision was 100% the other driver’s fault- a tiny, silent car is easy to miss when changing lanes in a giant truck, even if the car is painted a beautiful 1970s orange…but with Ontario’s “no fault” insurance program, you end up negotiating a settlement with your own insurer who then claims back from the at-fault driver’s policy holder. Sadly however, the program here has a settlement regime and dispute resolution mechanism baked right into the mandatory provincial insurance policy, even though the insurance is offered through private companies. When your car is damaged beyond repair, it is as if it goes up for sale that day- and the compensation is set based on the value that car would have fetched, that day, if sold rather than destroyed. The fact that there are very few converted cars in existence in Ontario- mostly as a result of insurance restrictions- is given no consideration. And if you dispute what you are offered, the process consists of an arbitration between the insurer’s appraiser and an appraiser you have to hire at your own cost, with the outcome determined by an “umpire”. So in the end, you accept what the appraiser gives you. In my case, that was less than the value of the parts I’d put into the car. I received zero compensation for the car or our labour.
You’ll notice though that despite extensive damage to BOTH sides of the car, including that rather serious damage to the front end in the photo above, the car did not catch fire, there were no electric shocks, and no other problems. The electric components came through the crash in good condition, and as part of the compensation package, I received the vehicle for salvage.
(chopping the car up into bite-sized pieces for the “urban raccoons” (salvagers who drive around town looking for scrap metal on garbage day) was one of the saddest days I’ve experienced)
The thought immediately turned to E-Fire Mark II- but Ontario’s insurance program put that idea entirely on the back burner.
Fortunately, just recently, I was able to find a willing insurer- one who I’d contacted previously and been denied by. A complaint to the Financial Services Commission of Ontario, the regulator of insurance companies in the province, led to a special connection with an insurer who will write a policy- with rather restrictive terms, but for a price which for a 3rd car in a 2 driver household, is roughly what I’m paying for my other two cars. That’s better than the Facility Association quote I had, which was four times that amount and which rendered the project impractical- but it’s still four times what I’d pay for an unconverted classic car of this vintage. Insurance for converted cars is still an issue requiring advocacy and change here.
With insurance under consideration, the likely victim for conversion is a 1973 TR6 that fell into my lap recently. It has a lovely, powerful 2.5L straight 6 cylinder engine with a deafening dual exhaust- but a bum transmission that may not be worth fixing. I’m not 100% decided at present, but I do very much miss electric classic motoring- and the TR6 is quite a looker compared to the E-Fire’s amateur restoration. It may be what I get up to this winter, but that’s not 100% certain at this point.
UPDATE: I finally broke down (after the TR6 broke down…) and converted the TR6. The ER6 was my COVID project, and has been motoring with the resurrected spirit of the E-Fire. See my article about that build!
There’s been a lot of talk recently about hydrogen as a replacement for natural gas. The scheme is to gradually add H2 to the natural gas grid, with the H2 being made from water using “excess” renewable electricity when it’s available. But ultimately, there are people who think we should have pure hydrogen supplied to our homes instead of natural gas, using the same piping and distribution network that we have now. In their minds, all we’d have to do is to re-jet all our boilers, furnaces, stove cooktops and ovens and we’ll be away to the races. No need to abandon all that expensive capital- we’ll just change the fuel! We’ll be burning colourless, odourless hydrogen, making only water vapour, and global warming will be one step closer to being solved.
Sounds great! Where do I sign?
Hold on- not so fast!
In case you prefer video to reading (I read far faster than I can watch anything, but to each their own!) Rosemary Barnes did an excellent video interview with me that used excellent graphics to get my points across- and asked excellent probative questions too. Well worth a watch- and the detail is here in the article you’ve already clicked on if you want to understand the issue more completely.
Replacing Gas With Hydrogen is An Inefficient Use of Energy
The first and most obvious criticism of this scheme is efficiency. It doesn’t matter if you start with natural gas or electricity, the best you can do is to convert about 70% of the feed energy (lower heating value (LHV) of methane, or kWh of electricity) into LHV of product hydrogen. Best case. If the alternative is to use natural gas or electricity directly, hydrogen brings nothing but loss to that equation.
Obviously the whole idea here is to eliminate the fossil greenhouse gas (GHG) emissions associated with the burning that’s happening at your end of their pipe. Hydrogen offers the option to do that. You can start with bio-methane from anaerobic digestion, so the CO2 you emit when you make hydrogen is just part of the natural carbon cycle. Or you can capture all or part of the CO2 produced when making hydrogen from fossil natural gas at the hydrogen plant, or by pyrolyzing the methane and selling carbon as a byproduct for uses other than burning, or you can avoid the CO2 entirely by making the electricity you feed your electrolyzer from wind or solar, nuclear, hydro, geothermal etc. These are all ways by which you could end up with a fossil GHG emission-free fuel for your burner- ideally that is, assuming you could afford it.
You could of course feed the grid with methane from biogas instead- but while I’m convinced biogas will be an important fuel for those fuel uses we really do need in a post-fossil future, nobody should try to convince you that there will be enough biogas EVER to just replace existing natural gas supplies- or even a small fraction of those supplies. So if you want to keep your burners, and not emit fossil GHGs, hydrogen seems like your only option. And that’s exactly what the natural gas industry is telling governments all over the world.
Of course, these gas companies and electrolyzer suppliers are not giving their advice without self-interest in mind. They are starting from the position that they need to stay in business, and you need to keep your burners- fair enough! The obvious alternative is to replace your burners directly with electricity and cut out the lossy hydrogen middleman, but that would leave them out of business. For home heating, and even for domestic hot water, a heat pump will not only save you the 30% conversion loss to hydrogen, it will also give you about 3 kWh worth of heat for every kWh worth of electricity you feed. Far, far more efficient. But not cheap- the heat pump is going to cost you quite a few dollars- and while renewable electricity is getting cheaper by the day, grid electricity still sells at a large multiple of the cost of natural gas per unit of energy- because carbon taxes are inadequate, and because in some places, fossil fuels still power the grid.
For your cooktop, an induction heater will give you even better performance than a flame- you may have to throw out a few of your old aluminum pots and pans, but otherwise you’ll likely be very happy with that change. And your oven will do nicely with a plain old resistance heater- with much better temperature control.
Remind me what we need a fuel gas for again, exactly? I know only one answer to that- right now, natural gas is a very, very cheap fuel IF you ignore the fossil GHG emissions from both its production and distribution and its burning. Displacing natural gas use from home heating is going to be a tough struggle regardless how we do it- because the alternatives are going to cost more, at least initially.
Note that the figure above is almost accurate- the distribution losses for hydrogen are exaggerated a bit due to a misinterpretation of a piece of data in a peer-reviewed article by Ulf Bossell, but even so- the efficiency of heatpumps may not be 5-6x better than hydrogen, but it’s at least 4-5x better…
Hydrogen, on the other hand, isn’t a cheap fuel, period. And it should be obvious that it can NEVER be as cheap as either the natural gas or the electricity from which it is made.
Hydrogen Distribution is Lossy and Expensive
Even assuming that you were so nostalgically attached to your gas appliances that you couldn’t part with them, the gas industry would still need to overcome some serious problems that aren’t being discussed, before hydrogen starts flowing through the natural gas grid.
If we’re going to make hydrogen, whether it’s “blue” hydrogen made from natural gas with carbon capture and storage, or “green” hydrogen made from water using renewable electricity, it still has to get from where it’s made to your house. And it’s not as simple as just changing what flows through the pipes.
Compression- the Deal Killer
To move any gas economically, it needs to be compressed. And it turns out this is the big problem with hydrogen distribution- it’s the reason that 85% of hydrogen produced in Europe, for instance, travels basically no distance to where it’s consumed, because it’s made right on the same site or right next door.
Natural gas is about 8.5 times as dense as hydrogen, and dense gases are easier (more energy efficient) to move than less dense ones. Hydrogen partially makes up for that fact by being more energy dense per unit mass- about 3 times as much as natural gas. But, sadly, the work (mechanical energy) needed to drive a compressor is related linearly to the number of moles of gas we compress, rather than to their mass or volume per se. It also depends, more weakly and in a more complex way, on the ratio of specific heats of the gas- which, as it turns out, makes a minor difference (in favour of natural gas) which increases with increasing compression ratio. But when we compare the LHV of hydrogen per mole to the LHV of natural gas per mole, we find that natural gas is about 2.9 times as energy dense in molar units. Another way to put it is that it takes about three times as much energy to compress a MJ’s worth of heat energy if you supply it as hydrogen than if you supply it as natural gas. And this, folks, at least in part, explains why we don’t move hydrogen around much by pipeline. Instead, we move natural gas to where hydrogen is needed, and build a hydrogen plant there. (see the end of the article for the proof)
That 3x increase in the work of compression not only costs energy, it would also cost a gas utility big money, since it would mean that every compressor in their network would need to be replaced with a new unit with 3x as much power, and also physically larger- with 3x the suction displacement. And since hydrogen is so notoriously leaky, the hydrogen volumetric flowrate is higher for a given heat flow in the pipe line etc., the compressors would need to be totally different machines- considerably more expensive ones.
Hydrogen is, already, round numbers, about 37% best case in cycle efficiency when starting and ending with electricity. Whereas natural gas and electricity are roughly the same cost and efficiency to distribute on a per unit energy basis, hydrogen is going to cost about 3x what natural gas costs in lost energy, just to move the gas. And since the downstream equipment is only 50-60% efficient at producing electricity again, you’re going to have to move roughly twice as MUCH hydrogen energy to destination to do the same job as if you moved electricity instead. That’s forgetting about the extra capital cost that would also need to be spent.
Pressure Drop in Piping- A Wash
You’d think that you’d suffer an additional penalty moving hydrogen through piping once you’d gotten it up to the desired pressure- that was certainly my first impression. But as it turns out, the answer to that question is quite complex, and it depends on what conditions you run the calculations at. Hydrogen is less dense, less viscous, and more energy dense per unit mass than natural gas. But when you run the pressure drop calculations at the sorts of velocities and pressure drops used in pipelines which carry gases long distances (where pressure drops are on the order of 5 psi per mile of pipe, rather than the 5 psi per 100 ft of pipe that might be typical in a chemical plant’s piping), hydrogen and natural gas come out nearly even at a given rate of LHV heat delivered per hour down a pipe of given size. That does change at different points in the distribution system, and to a 1st approximation, the average works out to an existing gas pipe being able to carry about 90% of the energy n the form of hydrogen that it could carry if it were fed the average natural gas it was designed for. The velocity will be about three times higher, but the density is 1/8.5x as much, and together with the modestly lower viscosity, the factors nearly cancel one another out. However, since every kWh of energy lost due to friction in the pipeline has to come from a compressor, that still means that hydrogen costs about 3x as much per unit of energy to move from source to destination in a pipeline.
“Line Pack”- What’s That? Another Problem…
As I promise my readers, I EDIT my articles when they teach me new things or point out my mistakes. And a knowledgeable connection brought to my attention this rather major problem that is a result of hydrogen’s lower energy density per unit volume. “Line pack” is the name given to the amount of natural gas stored in the piping distribution system itself. And unless we increase the pressure of the distribution system- which we cannot do without new pipe- we will lose that storage. A typical gas system apparently can handle about 3-4 hours of average demand just using stored gas in the lines. Pure hydrogen, being 1/3 as dense in energy per unit volume, would reduce that to ~ 1 hour. That could mean a giant difference in distribution system reliability, the frequency and duration of outages, and the ability of the grid as it exists to handle variations in demand- the big spike when everybody gets home, cranks up their furnaces or boilers and turns on their cooktops for instance.
I’m already aware that sometimes, subdivisions out-grow the rate at which the gas utilities can install new lines to them. Accordingly, some utilities evaporate liquid natural gas from tanks into points downstream of the “bottleneck” in order to keep the furnaces and cooktops humming through peak hours. Doing that with hydrogen would be very expensive and very dangerous, given that liquid hydrogen takes about 40% of the energy IN the hydrogen just to liquefy it, boils at 24 Kelvin (24 degrees above absolute zero- liquid methane boils at a balmy 112 Kelvin or -161 C)- and as a liquid it is still only 71 kg/m3- methane is about 420 kg/m3 in comparison as a liquid.
Piping and Equipment
If you don’t heat it up too much, hydrogen is quite safe to carry in mild steel piping- even up to fairly significant pressures. The much talked about “hydrogen embrittlement” isn’t a factor in relation to hydrogen gas handling for soft mild steel or low alloy steel piping such as what is used in most chemical plant piping.
However, natural gas pipelines- particularly the pipelines carrying natural gas long distances or underwater- are not made from mild steels. They’re made from harder, strong steels- and those steels are, according to many reports, susceptible to hydrogen embrittlement or other hydrogen related damage mechanisms, particularly in their welds and heat affected zones- even at fairly modest pressures and temperatures.
According to credible reports written by natural gas distribution utilities themselves, such as this excellent one:
-most of the high and medium pressure natural gas distribution system would need to be totally replaced to handle pure hydrogen. (see p.12 of that reference, where it says this in as many words- and these guys, who own the pipes, should know best!) That’s a massive cost- especially to spend on a change to a fuel which might be better replaced with electricity anyway.
Note that hydrogen damage and hydrogen embrittlement are complex metallurgical topics, and that nascent hydrogen (hydrogen atoms generated by electrochemical action such as during corrosion) causes damage that molecular hydrogen cannot until a combination of high pressure and high temperature make that possible. But the reports about H2 compatibility problems with pipelines used for natural gas is quite well demonstrated, by people who know this issue far better than I do.
Here’s another reference, from AIGA standard 087/20:
From Standard AIGA-087/20 (Asian Industrial Gases Association) Section 4.2.1- Metals
“… For high pressure applications, carbon steel shall be used with caution. Carbon steels with high-carbon content and high-strength, low-alloy carbon steels are susceptible to embrittlement and crack propagation. The use of carbon or alloy steels requires control of tensile strength, heat treatment, microstructure, and surface finish as well as initial and periodic examination for inclusions and crack-like defects when in cyclic service”
And another, from Sandia National Laboratories:
A webinar I attended (September 21, 2022) on the platform “Mission-Hydrogen”, confirmed these concerns. (A video recording of the webinar and of the presenter’s slides is available). The lecturer was Dr. Milos Djukic of the University of Belgrade, a senior fellow of the European Structural Integrity Society, whose summary paper on the issues related to hydrogen damage and embrittlement mechanisms in steels and alloys has been cited over 100 times. In the talk, Dr. Djukic confirmed that 1-5% H2 is enough to cause worries about hydrogen assisted fatigue crack growth, that fatigue can be accelerated by more than 10 times (indeed Dr. Djukic confirms the rate may increase up to 30 times), and fracture resistance can be reduced by more than 50%, and that all the normal high yield stress API grades of pipeline steel are susceptible. Dr. Djukic concluded in his talk as follows (emphasis is his):
“It is widely believed that existing gas pipelines that are retrofitted for transportation of natural gas-H2, CH4-H2 and N2-H2 gas mixtures, and repurposed for 100% H2 transport, are viable options and safe for long term future usage. However, despite the fact that gaseous H2 transport via existing gas pipelines is a low-cost option for delivering large volumes of H2, there is a serious threat of hydrogen damage and catastrophic failure, particularly for old-aged gas pipelines, after future long-term H service. “
UPDATE April 2023: a recent study paid for by German gas and water association DVGW proves, by careful measurement, that the materials used in gas pipelines- even low yield strength versions- suffer from accelerated fatigue cracking and reduced fracture toughness, even in some cases at fairly low hydrogen partial pressures. However the study claims that it’s OK, because the cracking doesn’t happen faster and the fatigue resistance doesn’t drop sufficiently to fall outside the limits of dedicated hydrogen piping design code ASME B31.12- a code that fossil gas pipelines are NOT designed and fabricated to.
Under the hydrogen design code, the design pressure of an existing fossil gas line would need to be de-rated to perhaps 1/2 to as little as 1/3 of its original rating if it were switched to carry hydrogen. That’s going to have a very large impact on the energy carrying capacity of those lines, likely necessitating either twinning or replacement of any transmission line switched to hydrogen. And it stands to reason that “twinning” would need to be in the cards anyway, as in any realistic transition scenario there will be a time when a transmission system would need to supply both hydrogen AND fossil gas to its customers. Hmmm…the notion that you can re-use this infrastructure meaningfully is looking less and less promising the more we look into it!
However, piping designed not to leak natural gas can leak a lot of hydrogen due to hydrogen’s low density and high diffusivity. Intact HDPE piping and the seals and other “soft goods” used in the distribution system are quite permeable to hydrogen. And, sadly, stenching agents such as the thiols (mercaptans) used in natural gas to help detect leaks, may be used in hydrogen for burning, but not with hydrogen to be used to feed PEM fuelcells such as those used in vehicles. The catalysts in those fuelcells are extremely sensitive to sulphur compounds like that. Given hydrogen’s extremely wide explosive range- any mixture between 4% and 75% hydrogen in air is explosive- and its low ignition energy- the lack of a stenching agent to help you detect leaks seems a very challenging problem for distribution of this fuel to homes and businesses.
Hydrogen/Natural Gas Mixtures
The initial projects all try to smooth over these problems by mixing a little H2 into natural gas instead of making the big leap to pure hydrogen. And when you hear about “replacing 20% of natural gas with hydrogen”, you’d think that would make a big difference!
Think again.
A 20% mixture of H2 in natural gas is a 20% mixture by volume. That mixture has only 86% of the energy of an average natural gas, meaning that you’d have to burn 14% more volume of gas to make the same number of joules or BTU of heat. The savings in GHG emissions are nowhere nearly 20%- they’re closer to 7% just looking at the burning (assuming perfectly carbon free green hydrogen), and less than that when you consider the compression and pressure loss noted above. Such a reduction would already cause heat content sensitive users to scream, so forget about going to 30% H2! For a given amount of energy delivered, a 20% mixture of hydrogen in natural gas would take 13% more energy to compress and would lose about 10% more pressure per unit length of pipe than if you were to stick with natural gas- because the gas has to flow faster, and yet isn’t sufficiently lower in density to compensate. Those factors would eat some of your GHG emission savings. And while industrial users would be protected- they pay per BTU or joule of LHV or HHV they are delivered by the gas company- some users could be shortchanged since they pay per unit volume instead.
(Image Credit: Rosemary Barnes, from her Engineering With Rosie video, link previously provided)
Of course, to get ANY meaningful reduction in GHG emissions, you need to use “green” hydrogen (made by electrolysis using fossil-free energy). That doesn’t exist meaningfully in the market at present- it is too expensive. So what is brought to the rescue? So-called “blue” hydrogen, made the normal way, from fossils, but with carbon capture and storage (CCS). Sadly, that approach makes only muddy blackish-blue, bruise-coloured hydrogen at best, as this paper by Howarth and Jacobson published in Environmental Science and Engineering makes clear. Fossil advocates have pooh-poohed the paper because it uses methane emissions higher than they’d like to admit to, and because it uses the 20 yr time horizon greenhouse potential of methane relative to CO2 which is 86x CO2. But even if you use the sensitivity analysis in the paper to trim back the estimated methane leakage, and you imagine that all “blue” hydrogen production will use new oxy-blown autothermal reformers so carbon capture can be more complete, “blue” hydrogen appears to be a very poor strategy for decarbonization. It is, in contrast, an excellent strategy in the view of the fossil fuel industry, because their objective is to stay in business, not to decarbonize anything really.
Another excuse we hear for the need for hydrogen to replace natural gas is for “high temperature industrial heating”. For some reason, people just seem to assume that because we run some equipment right now by burning fuels, we cannot instead use electricity. The examples of steel and cement-making are frequently brought up, but there are many others.
Here I have to bring in what I do for a living. I design and build pilot plants, which are prototype units to test new chemical processes. These plants can vary from tiny lab units to quite large facilities that would look to the average person like any other real chemical plant. But the one thing that a pilot plant will almost entirely without exception be missing is any fired equipment. There are exceptions, but aside from the function of disposing of waste streams of combustible materials, every function that is accomplished on a commercial chemical plant using fired equipment, is done using electricity instead on a pilot plant. Why is that?
Many reasons:
1) Electricity is far safer and easier to control than fire, particularly at the small scale. Electric heating provides rapid, accurate control and reduces hot spots, reduces risks to materials of construction etc.
2) Electricity costs more than fuel as a heat source, but the energy cost of a pilot plant is seldom the most important factor to its operators.
3) Fired heaters generally need air emissions permits and may require stack gas testing- costs which the pilot plant avoids by using electric heating.
4) To heat a stream to high temperatures using a burner, you are left with a high temperature flue gas exiting the unit. Chemical plants make use of that hot flue gas to heat up numerous other streams to keep it from going to waste- or use it to make steam to drive equipment or keep things hot. On a pilot plant, it is just not worth the trouble of doing that kind of heat integration
5) Fired equipment is more expensive than electrically heated equipment
6) When you need the highest temperatures, sometimes electric heating is the only feasible option.
In steelmaking, the real need for hydrogen isn’t for heating at all- electric arc furnaces for steelmaking are already quite popular. Hydrogen is needed to replace the chemical reductant carbon monoxide made from coal coke, which is used to reduce iron oxide to iron metal. There are direct electrochemical reduction methods also under development, so it’s possible we could also make steel without using hydrogen at all.
In many other applications, electric heating could easily be used to eliminate the need to burn fuels. It would however require modification to major pieces of equipment, which might have a considerable cost. But if the alternative is to spend a multiple of that cost on hydrogen made FROM electricity, that savings can pay for quite a bit of capital.
In fact, if approached with a fresh sheet of paper and without a firebox on your head, most applications in industrial heating currently served with fire for cost reasons (because fuels are cheaper, as long as you can dump fossil CO2 to the atmosphere), could easily be converted to electric heating instead.
All we really need is to price fossil carbon emissions at a rate high enough- and durably enough- to make the associated capital investments worthwhile in economic terms for the affected industries.
Hydrogen Toxic Emissions
You will frequently hear the old trope that when you burn hydrogen, you get nothing but water! While that IS true if you “burn” hydrogen catalytically in a low temperature fuelcell, it is NOT true in general terms.
Burning ANYTHING in air results in nitrogen oxides (NOx) being generated by reaction between oxygen and nitrogen in the air. The higher the combustion temperature, the more NOx you generate. And the more H2 you add to a natural gas mixture, the higher the resulting free air combustion temperature will be- and hence, the higher the NOx emissions will be.
NOx consists of two important nitrogen oxides and one transient species. NO2 is the dangerous brownish gas which is toxic, produces “acid rain”, and is a photochemical smog precursor. It is however quite water soluble (hence the acid rain) and so it isn’t environmentally persistent.
N2O (nitrous oxide) isn’t toxic- it’s used as an anaesthetic and it may even be produced in our own bodies. It is however a powerful, persistent GHG with a 100 yr greenhouse potential of 300x that of CO2.
Industrial combustion equipment burning hydrogen or H2-rich mixtures can be fitted with selective catalytic reduction (SCR) units, which react NOx with hydrogen to produce N2 and water again. Not so with home appliances though- it is fundamentally impossible with things like cooktops for obvious reasons, and it is economically impractical with devices like furnaces, rooftop heating units, hot water heaters and heating boilers too.
This issue seems to be conveniently forgotten. Natural gas burning in homes is already a major source of indoor air pollution and apparently also a major cause of juvenile asthma. Hydrogen will make that worse, not better, relative to natural gas.
Flame Visibility
Don’t let the stupid “hydrogen olympics” fool you. Hydrogen flames are rich in the UV and emit very limited amount of visible light. They are visible only at night, unless the H2 is contaminated with something. The Olympic flame was contaminated deliberately with sodium carbonate, giving it the eerie orange glow from the spectral emission lines of sodium.
Hydrogen for Seasonal Energy Storage
Another argument that I frequently hear is that because of the double whammy of greater energy need for heating and lower solar power production in winter, we’ll need hydrogen to make up the shortfall. We’ll need to make vast quantities of hydrogen in summer, and store it in salt caverns until winter. While stored fuels of some kind are likely a useful part of an emergency response plan in any post-fossil fuelled future, it is to me a non sequitur that just because it’s possible to use hydrogen for this purpose, that doing so would actually make energetic or economic sense. Methane, whether from biogas or even fossil natural gas, seems a more logical choice as a gas to store, given that we already have strategic and emergency stores of natural gas in place. And we could just as easily store up a year’s worth of biogas methane as we could find a way to make hydrogen in excess in summer.
Green hydrogen’s chief economic problem as an energy storage medium is the cost of electrolyzers and storage equipment- and as we’ve seen in this paper, distribution cost isn’t going to be as low as some expect either. Multiplying the low capacity factor of a wind or solar production unit by another seasonal capacity factor of say 0.5 or less, doesn’t add up to a low capital cost per kg of hydrogen stored. This stored fuel would be very expensive indeed, even if the power itself were quite cheap.
Why Are We Doing This Again?
NREL’s document issued in October 2022 about hydrogen blending (see https://www.nrel.gov/docs/fy23osti/81704.pdf) contains a very good summary of the challenges involved in replacing fossil gas with hydrogen, including this excellent table:
In summary, it seems to me quite clear that hydrogen’s role as a replacement for natural gas has more to do with a need for gas production and distribution companies to stay in business by having something to sell, than any real GHG emissions benefit or significant technical need. And if they want to make the necessary investments entirely on their own nickel, to provide truly green or even “blue” hydrogen via an upgraded network to replace natural gas, perhaps that’s OK with me. Sadly, it seems quite clear that their caps are in hand, reaching out to the public sector to fund the necessary infrastructure investments. Personally, my thinking is that this would be throwing good money after bad.
DISCLAIMER: these are my personal opinions, informed by my knowledge and practice of chemical engineering over the past 30 yrs. My opinions are my own, and are not to be confused with those of former employers or current or former clients. I am motivated only by a sincere desire to get us off fossil fuels and by so doing, eliminate fossil GHG and toxic emissions associated with burning them, for as low a cost and impact on society as we can manage. Every article I write is likely to make one or another of my customers angry- you can rest assured of that!
I have made my best effort to be accurate in what I’ve said, doing my own confirmatory calculations. I can provide background on those to anyone who asks. But I’m human, and hence prone to error. I also don’t for a moment claim to know everything there is to know about this subject matter, which is where some people have spent their entire careers. If you can show me where I’ve gone wrong in my analysis or calculations, with references or dependable examples, I’ll gratefully edit my piece to reflect these new learnings on my part.
APPENDIX:
Here’s the abbreviated logic behind why it takes 3x as much compressor energy to move a given amount of H2 LHV as to move the same number of J or BTU of natural gas LHV.
Where a and b are constants, different for each gas, but only a little different between H2 and natural gas, and r is the compression ratio i.e. P2/P1, P1 is the initial absolute pressure and V1 is the initial volume, the work of adiabatic compression is given by a formula of the following form:
W = a P1V1 (1-r(1/r)^b)
Per the ideal gas law, P1V1 = nRT1, where n is the number of moles of gas, R is the ideal gas constant, and T1 is the initial temperature.
Taking gases 1 and 2 of nearly equal values of a and b (to avoid getting results which vary with r), and taking them at the same initial pressure, volume and temperature, it can be shown that:
W1/W2 = ~ n1/n2
Hydrogen has a molar LHV of 240 kJ/mol, and a middle of the road natural gas might have a LHV of 695 kJ/mol. The work ratio is therefore ~2.9:1 for hydrogen versus natural gas, if we were to move a constant number of kJ of LHV per compression stroke, or per unit time.
The actual values of a and b (related to the Cp/Cv ratio) for H2 and natural gas at commercially significant compression ratios adjust this 2.9:1 ratio to about 3:1.
