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!
Warning: this article contains a lot of numbers. Numbers that tell a story. If you don’t like numbers, stop reading and spare yourself arithmetic anxiety.
It should not be news to you that people in Canada need to heat their homes. Some of us also need air conditioning if we want to be able to sleep in hot, humid July and August.
Home heating- emissions from residential combustion sources, resulted in 41 MT of CO2 equivalent emissions in 2017, or about 7% of Canada’s national GHG emissions. In contrast, road transport represented 141 MT- about 25% of total GHG emissions. Public electricity and heat production, lumped together, are larger at 79 MT. Oil and gas production and refining are larger still at 124 MT. Home heating is actually a surprisingly small fraction of our national and per capita emissions, given our cold climate. Figures are from Table ES-2 in this reference:
About 75% of Canadians- those of us living in Ontario, Quebec, Manitoba and British Columbia for instance- have access to an electrical grid which is extremely low in CO2 emissions. Ontario is highest in that group with 40 g CO2/kWh on average. All of those GHG emissions comes from the 6% of our grid power produced using natural gas. We burned our last coal for power in 2013. It’s an enviable situation that much of the world can only dream of achieving decades from now.
Most Canadians, who live in major or secondary urban centres, also have access to the natural gas distribution system. And those who do, almost exclusively use natural gas to heat their homes through long Canadian winters.
Why? One reason: price. Natural gas is, and has long been, the cheapest source of heat available to homeowners- as long as they are in a city or town on the natural gas grid.
Those who don’t- people who live in rural locations or a few provinces without natural gas distribution- have four choices: wood or wood pellets, propane, fuel oil or electricity. Wood is often used as either a primary or supplementary heat source in rural locations or for cottages and hunting camps, with back-up often provided by electric resistance baseboard heaters. Rural homeowners are otherwise left with expensive options: propane sells at a premium to natural gas, oil tends to be used only in very old houses which haven’t had their heating systems retrofitted yet, and although electrical resistance heaters are 100% efficient at converting work (electricity) to heat, they are very expensive to operate.
So natural gas heating is king in Canada. My own home is heated with a modulating condensing boiler with an annual fuel utilization efficiency (AFUE) of about 94%. . My domestic hot water is similarly produced by a flow-through modulating condensing water heater with an AFUE of 98%. AFUE is a measure of how much of the chemical potential energy of a fuel, measured by its HIGHER heating value (HHV), is converted into useful heat in the home. High AFUE appliances not only extract the heat from the combustion product gases, but also extract heat by condensing the water produced by combustion.
Natural gas is very cheap per unit of chemical potential energy. One cubic metre of natural gas has a typical HHV of 37 MJ – for comparison, that’s about 10.3 kWh. But it is important not to confuse heat energy (which the HHV of natural gas represents) with thermodynamic work- which electricity can be readily converted to.
My house used 2677 m3 of natural gas in 2018, which cost including taxes $1184 CDN, or $0.42 per m3. Of that, $271 were account fees and taxes on those fees, rather than the marginal cost of extra gas and its delivery.
Fed into my 94% AFUE boiler, that’s about 4.3 cents/kWh worth of useful heat, i.e. if we were to compare it to a 100% efficient electrical resistance heater. To look at it another way, for every m3 of gas I burn in my boiler, I get about 9.7 kWh worth of useful heat in my house. The average cost of electricity for us in 2018 in contrast was about 17 cents per kWh.
In GHG emissions terms, combustion and upstream/transmission energy use result in emissions of about 1.9 kg CO2/m3. That means for every kWh of heat my 94% boiler puts into my house, carbon emissions are about 0.2 kg or 195 g. In comparison, Ontario’s electricity CO2 generation is about 40 g total per kWh. In direct CO2 emissions from source, that’s about 4.9 times what I’d emit from my house if I used electric resistance heaters instead.
If we were to add estimates of methane leakage in production and distribution per my other paper:
-of 2.5 to 5% of the methane fed, using the 20 yr 86x factor for methane’s GHG equivalence to CO2, that would increase my heating plant’s GHG emissions from 195 g of actual fossil CO2 emitted to between 343 and 491 g of CO2 equivalent per kWh. That’s between 8.6 and 12.3 times as much total CO2(equiv) on the 20 yr time horizon as if I heated with electric resistance heaters. Environment Canada estimates fugitive emissions of GHGs from oil and natural gas production to be about 54 MT- more than the amount produced by all residential heating combined. They no doubt use the 100 yr 33x factor for methane vs CO2 in this estimate.
The house used 2677 m3 of natural gas last year. That’s all heating, domestic hot water and our cooktop and oven, but not the clothes dryer which is electric. My CO2 emissions were therefore 5.06 T of direct or 8.9 to 12.7 T of total CO2(equiv) including the 2.5 to 5% methane leakage factor. $1124 per year to meet all the heating needs of a roughly 2400 sq ft 2 storey house and a family of four. It’s a relatively efficient house, about half renovated 1920s and half modern, well-insulated addition with careful detailing. Better than average, not best in class.
For comparison, I commute 4 days per week, 122 km total per day. My commute in my 5L/100 km Prius C amounts to some 3.4 T of CO2 emissions from source, plus the associated toxic emissions breathed by the people I drive by on my way to and from work. That’s for one person to earn a living. A substantial fraction of the direct GHG emissions to keep a family of four warm through a Canadian winter, despite this being the most efficient IC engine car you can currently buy in Canada that doesn’t also have a plug. (Sure- I could move closer to work- but my options there are putting my wife out of HER career, and also quite likely a divorce. Not a practical option I’m afraid!)
Also in comparison, we have high speed internet, a VoIP home phone plan, and three cellphone plans, all modest and none with cellular data. Telecom services cost our family a total of $1650 per year. Yes, telecom services are expensive in Canada due to lack of competition and low population density. But we pay about 1.4 times as much for telecommunications as we pay to heat our house, in part because in 2018 we paid nothing to dump CO2 and methane to the atmosphere. Is that a correct statement of our relative values?
Recently, Canada’s federal government implemented a minimum carbon tax standard for the country. Ontario had a working cap and trade system with Quebec and California, but our provincial government elected about a year ago, spent hundreds of millions to destroy that working system- only to have it replaced by the federal government’s tax. The tax, per my most recent bill, was 3.91 cents per m3, or $20 per tonne of direct CO2 emissions ($8.50 per tonne of total 20 yr equivalent emissions at the 5% leakage figure). That would have increased my 2018 bills by $105, or nearly 10%.
My average electricity use costs me 17 cents per kWh- that’s the total of my 2018 bills divided by my home’s total kWh consumption. Electricity in Ontario has time of use rates, so electricity is cheaper at night than during peak hours during the day. But if I were to use my average cost per kWh to run resistance heaters, my heating bill would have been $4420 last year. My CO2 emissions would have dropped to about 1 tonne. That’s a $3300/yr increase in cost, to save 4 tonnes of real or up to 11.7 tonnes of CO2 equivalent emissions. A cost of between $820 and $280 per T of emissions averted.
Needless to say, we’d have noticed that extra cost- if we were to increase our heating costs by a factor of almost four.
Of course there are alternatives to resistance heaters! A heat pump can use work (electricity) to pump heat from a cold place (the air, or the subsurface). Air source heatpumps became briefly popular in Canada after the 1973 energy crisis, but fell rapidly out of favour again due to the poor durability and performance of the first generation units in extremely cold weather. Modern air-source heat pumps can generate a coefficient of performance (COP) of up to 2 at temperatures as low as -20 C. It rarely gets colder than -20 C in Toronto or Vancouver, but does in places like Calgary, Edmonton, Regina and even Montreal. Air source heat pumps are a modest cost increase over air conditioners, which happen to also be basically necessary in the warmer parts of Canada due to hot, humid summers.
Small Mitsubishi air source heat pump units deliver their full heating load at 21 C return air temperature and outdoor temperatures of -15 C. Coefficients of performance- the kW of heat pumped into the interior per kW of power used- range from about 1.5 at -25 C outdoor to about 3.4 at 5 C outdoor. An air-sourced heat pump unit returning a COP of 2.2 would have reduced my electric heating cost to $2010/yr. if I were to go all electric- again this is an approximation because the HP system wouldn’t heat my domestic hot water or fire my cooktop or oven. That is still almost twice what I paid for natural gas last year. There is therefore no payback to be had from installing an air-source heat pump, until carbon taxes become very substantial indeed.
Another alternative is ground sourced heat pumps. In urban areas, groundsource heat pumps require vertical wells to be drilled as there is insufficient land for heat collection trenches to be effective. Drilling costs vary, as do the cost of the equipment and installation, but it is clear that the costs of a groundsource heat pump system are many times the cost of a conventional furnace and air conditioner which they replace. Ground source systems can have coefficients of performance ranging from 2.5 to 5 for heating, with the bonus being that the COPs for cooling are very high indeed- air conditioning basically becomes “free”.
As a best case, assuming a system with a heating COP of 5, my electric heating costs would drop to $882 per year, a savings of $241 per year versus my current cost for natural gas heating. But $241 per year would never pay back the extra cost of that GSHP system. Real savings would be modestly larger because it would drop my cost for air conditioning. A rough estimate is that we spent a whopping $95 on air conditioning in 2018 as best I can estimate, by comparing our June, July, August and September electricity bills against our May and October bills- so not much to be saved there.
Significant carbon taxes would be required to make this investment make economic sense to someone whose primary interest was saving money rather than the planet. And frankly, if we’re honest, our actions and decision reveal that most of us don’t care much about either: we care far more about our own comfort and convenience.
Perhaps this analysis explains why my focus has been on the electrification of transport, rather than on heating. Savings in GHG emissions of 97% and a halving of daily operating costs can be achieved simply by switching from IC engine to battery electric cars and light trucks. The electrification of light personal transport is some of the lowest hanging fruit in the battle against global warming in my opinion. Heating, on the other hand, will definitely have to wait.
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.
First of all, #hopium isn’t my original idea. I would attribute the use of the term to the person who I first heard use it, but sadly I’ve forgotten. The moment I heard it, I knew this was the ideal description of a problem I’d been seeing in numerous areas of our attempt to decarbonize our economy. I now use it as a hashtag when I identify its use, when I see it.
Hopium is a merging of the words “hope” and “opium”. When I use it, I mean the conversion of our hope into a drug that compromises our ability to analyze and make good judgments about new technology.
Hopium is the fuel of “green-wishing”, without which, green-washing wouldn’t be possible. Greenwishing is wishful thinking which has us conclude, without a basis in fact, without the necessary weighing of benefits against disadvantages, that a particular new thing is going to be our decarbonization salvation. And greenwishing is at epidemic proportions. We’ve spent the past 30 yrs basically hoping that engineers like me will come up with some “deus ex machina” solution to the AGW risk, which will allow us to go on living the exact same way we’ve been living, with no compromises, no extra costs, no carbon taxes so we stop treating the atmosphere like a free public sewer.
On hope: I’m with the great German author Goethe, who famously said, “In all things, hope is preferable to despair.” I qualify Goethe’s comment though, by saying that in order for hope to be worthy of us, our hope can’t be contrary to the most basic laws of the universe. False hope which can be demonstrated clearly to be false is more than merely a distraction- it’s a tool used by hucksters to separate us, and our governments, from our money.
Deus ex machina- god from the machine- by DALL-E
The “opium” aspect is largely a result of either our ignorance of physical laws and of basic science, or our ridiculous willingness to set them aside when it sounds like it would make a good story or would solve our problems.
The delivery mechanism of hopium is marketing hyperbole. It isn’t just limited to the telling of lies or the spreading of misinformation that would lead to the false conclusion that something bad is actually good. It is the exaggeration of claims and neglecting to mention the limitations within which a technology, new or old, is of use- and where it goes off into the ditch and becomes a liability. It is telling the truth with head nodding “yes”, without telling any of the truth with head nodding “no” that we need to fully understand the issues.
While it’s natural for people selling things to put a positive spin on their product or service, what drives me to drink (and it’s not a far drive most days!) is when JOURNALISTS do this. When journalists fail to even ask the questions necessary to establish whether what they’ve been given is just a sales pitch or a realistic alternative. Of course that’s a big part of the problem right there- the loss of real journalism in the Internet era. Writers become salespeople whose job is to generate “clicks”, not to inform the public.
While I use the #hopium hashtag most often in relation to the so-called “hydrogen economy” predicated on the use of hydrogen as a fuel, it is by no means restricted just to hydrogen. Rather intense hopium slinging is rife in relation to battery development. In fact, it has long been so- Edison said as much:
“Edison warned that chasing the perfect battery is a fool’s journey: “a catchpenny, a sensation, a mechanism for swindling the public by stock companies,” he wrote. Working on the latest, greatest battery brings out a man’s “latent capacity for lying.”
But hopium is also rife in relation to carbon capture and storage schemes and particularly the foolishness known as “direct air capture”. If you’re interested in this, you can’t do better than @Michael Barnard’s brilliant take-down of Carbon Engineering, who Michael aptly refers to as “Chevron’s Figleaf”
Small modular nuclear reactors, especially the thorium ones, are another clear example. They rely on an ignorance of the PAST of nuclear power, and of the most elementary engineering economics. They are extraordinarily unlikely to EVER make cheap kWh.
In the most delicious irony, Hopium is also the chosen name of a French hydrogen fuelcell car company – fuelcell cars being to me the epitome of a bad idea which has been known for decades to be a bad idea, and yet hope for it springs eternal- and public money keeps being poured down this particular black hole long after its best before date.
What did Hopium choose to call its first car model? The Machina, of course. You can’t make sh*t up better than this…
I often say that I have a high tolerance to hopium because I was once a hopium addict myself. I was a true believer in hydrogen, until I spent a couple years working directly on a project trying to make small reformers and other equipment for making hydrogen to supply fuelcells. It was intense study and practice with the material which woke me up to what others have known about it for a considerable period of time.
What’s the antidote to hopium? Information and analysis done by disinterested parties. I try my best to be part of that. And when I believe firmly that a technology has promise and is a good solution, I do try my best to establish the limits within which that conclusion is accurate. Electric vehicles being just one such for-instance. My first article about energy and decarbonization matters was in fact written to take on a #hopium fuelled fallacy popular in the EV media at the time.
I also co-wrote with James Carter a series of articles which were quite popular with readers but not with the media outlet who chose to publish it…they like telling happier stories I guess.
How can you help to combat the #hopium epidemic? Well, sharing my articles is a help! Nobody is paying me to write them, and they are not written in response to personal or professional financial interest. My employer disavows all connection with my efforts, even when it sometimes brings them business, because it also brings out people who try to silence me by means OF my employer. They would prefer me to shut up about this stuff! But I have the opportunity to speak out and at this point in my career, I see that as a responsibility.
I advise you as my sister did: keep an open mind, but not so open that your brain falls out of your head. And be cautious and skeptical rather than being automatically negative- that can have you buying into nirvana fallacy arguments against things which really could be effective to help us with decarbonization. And work on solutions- real solutions, rather than easy ones. Here’s my suite of solutions- I mis-numbered them so there’s one left for
And lastly, be wary of anything anyone asks you to eat, smoke or drink…
And be wary about my alter-ego. You can tell him not only by what he says, but by his beard of bees…
All my concerns about hydrogen #hopium, in one convenient place!
Hydrogen is being sold as if it were the “Swiss Army knife” of the energy transition. Useful for every energy purpose under the sun. Sadly, hydrogen is rather like THIS Swiss Army knife, the Wenger 16999 Giant. It costs $1400, weighs 7 pounds, and is a suboptimal tool for just about every purpose!
The Wenger 16999 Giant (the Wenger brand is discontinued- owned by Victorinox)
Why do you hate hydrogen so much? I DON’T HATE HYDROGEN! I think it’s a dumb thing to use as a fuel, or as a way to store electricity. That’s all.
I also think it’s part of a bait and switch scam being put forward by the fossil fuel industry. And what about the electrolyzer and fuelcell companies, the technical gas suppliers, natural gas utilities and the renewable electricity companies that are pushing hydrogen for energy uses? They’re just the fossil fuel industry’s “useful idiots” in this regard.
If you prefer to listen rather than read, I appeared as a guest on the Redefining Energy Podcast, with hosts Laurent Segalen and Gerard Reid: episodes 19 and 44
…or my participation in a recent Reuters Renewables debate event, attended by about 3000
This article gives links to my articles which give my opinions about hydrogen in depth, with some links to articles by others which I’ve found helpful and accurate.
Hydrogen For Transport
Not for cars and light trucks. The idea seems appealing, but the devil is in the details if you look at this more than casually.
When you look at two cars with the same range that you can actually buy, it turns out that my best case round-trip efficiency estimate- 37%- is too optimistic. The hydrogen fuelcell car uses 3.2x as much energy and costs over 5.4x as much per mile driven.
For trucks- I agree with James Carter- they’re going EV. EVs will do the work from the short range end of the duty, and biofuels will take the longer range, remote/rural delivery market for logistical reasons. Hydrogen has no market left in the middle in my opinion.
Trains: same deal.
Aircraft? Forget about jet aircraft powered by hydrogen. We’ll use biofuels for them, or we’ll convert hydrogen and CO2 to e-fuels if we can’t find enough biofuels. And if we do that, we’ll cry buckets of tears over the cost, because inefficiency means high cost.
(Note that the figures provided by Transport and Environment over-state the efficiency of hydrogen and of the engines used in the e-fuels cases- but in jets, a turbofan is likely about as efficient as a fuelcell in terms of thermodynamic work per unit of fuel LHV fed. The point of the figure is to show the penalty you pay by converting hydrogen and CO2 to an e-fuel- the original T&E chart over-stated that efficiency significantly)
Ships? There’s no way in my view that the very bottom-feeders of the transport energy market- used to burning basically liquid coal (petroleum residuum-derived bunker fuel with 3.5% sulphur, laden with metals and belching out GHGs without a care in the world) are going to switch to hydrogen, much less ammonia, with its whopping 11-19% round-trip efficiency.
Fundamentally, why do we burn things? To make heat, of course!
Right now, we burn things to make heat to make electricity. Hence, it is cheaper to heat things using whatever we’re burning to make electricity, than it is to use electricity. Even with a coefficient of performance for a heat pump, so we can pump 3 joules of heat for every joule of electricity we feed, it’s still cheaper to skip the electrical middleman and use the fuel directly, saving all that capital and all those energy losses.
Accordingly, hydrogen- made from a fuel (methane), is not used as a fuel. Methane is the cheaper option, obviously!
In the future, we’re going to start with electricity made from wind, solar, geothermal etc. And thence, it will be cheaper to use electricity directly to make heat, rather than losing 30% bare minimum of our electricity to make a fuel (hydrogen) from it first. By cutting out the molecular middleman, we’ll save energy and capital. It will be cheaper to heat using electricity.
I know it’s backwards to the way you’re thinking now. But it’s not wrong.
Replacing comfort heating use of natural gas with hydrogen is fraught with difficulties.
Hydrogen takes 3x as much energy to move than natural gas, which takes about as much energy to move as electricity. But per unit exergy moved, electricity wins, hands down. Those thinking it’s easier to move hydrogen than electricity are fooling themselves. And those who think that re-using the natural gas grid just makes sense, despite the problems mentioned in my article above, are suffering from the sunk cost fallacy- and are buying a bill of goods from the fossil fuel industry. When the alternative is to go out of business, people imagine all sorts of things might make sense if it allows them to stay in business.
Hydrogen as Energy Storage
We’re going to need to store electricity from wind and solar- that is obvious.
We’re also going to need to store some energy in molecules, for those weeks in the winter when the solar panels are covered in snow, and a high pressure area has set in and wind has dropped to nothing.
It is, however, a non-sequitur to conclude that therefore we must make those molecules from electricity! It’s possible, but it is by no means the only option nor the most sensible one.
The reality is, black hydrogen is much cheaper. And if you don’t carbon tax the hell out of black hydrogen, that’s what you’re going to get.
Replacing black hydrogen has to be our focus- our priority- for any green hydrogen we make. But sadly, blue (CCS) hydrogen is likely to be cheaper. Increasing carbon taxes are going to turn black hydrogen into muddy black-blue hydrogen, as the existing users of steam methane reformers (SMRs) gradually start to capture and bury the easy portion of the CO2 coming from their gas purification trains- the portion they’re simply dumping into the atmosphere for free at the moment.
There is no green hydrogen to speak of right now. Why not? Because nobody can afford it. It costs a multiple of the cost of blue hydrogen, which costs a multiple of the cost of black hydrogen.
The reality is, you can’t afford either the electricity, or the capital, to make green hydrogen. The limit cases are instructive: imagine you can get electricity for 2 cents per kWh- sounds great, right? H2 production all in is about 55 kWh/kg. That’s $1.10 per kg just to buy the electricity- nothing left for capital or other operating costs. And yet, that’s the current price in the US gulf coast, for wholesale hydrogen internal to an ammonia plant like this one- brand new, being constructed in Texas City- using Air Products’ largest black hydrogen SMR.
At the other end, let’s imagine you get your electricity for free! But you only get it for free at 45% capacity factor- which by the way would be the entire output of an offshore wind park- about as good as you can possibly get for renewable electricity (solar here in Ontario for instance is only 16% capacity factor…)
If you had 1 MW worth of electrolyzer, you could make about 200 kg of H2 per day at 45% capacity factor. If you could sell it all for $1.50/kg, and you could do that for 20 yrs, and whoever gave you the money didn’t care about earning a return on their investment, you could pay about $2.1 million for your electrolyzer set-up- the electrolyzer, water treatment, storage tanks, buildings etc.- assuming you didn’t have any other operating costs (you will have). And…sadly…that’s about what an electrolyzer costs right now, installed. And no, your electrolyzer will not last more than 20 yrs either.
Will the capital costs get better? Sure! With scale, the electrolyzer will get cheaper per MW, as people start mass producing them. And as you make your project bigger, the cost of the associated stuff as a proportion of the total project cost will drop to- to an extent, not infinitely.
But the fundamental problem here is that a) electricity is never free b) cheap electricity is never available 24/7, so it always has a poor capacity factor and c) electrolyzers are not only not free, they are very expensive and only part of the cost of a hydrogen production facility.
Can you improve the capacity factor by using batteries? If you do, your cost per kWh increases a lot- and that dispatchable electricity in the battery is worth a lot more to the grid than you could possibly make by making hydrogen from it.
Can you improve the capacity factor by making your electrolyzer smaller than the capacity of your wind/solar park? Yes, but then the cost per kWh of your feed electricity increases because you’re using your wind/solar facility less efficiently, throwing away a bunch of its kWh. And I thought that concern over wasting that surplus electricity was the whole reason we were making hydrogen from it!?!?
John Poljak has done a good job running the numbers. And the numbers don’t lie. Getting hydrogen to the scale necessary to compete with blue much less black hydrogen is going to take tens to hundreds of billions of dollars of money that is better spent doing something which would actually decarbonize our economy.
UPDATE: John’s most recent paper makes it even clearer- the claims being made by green hydrogen proponents of ultra-low costs per kg of H2 are “aspirational” and very hard to justify in the near term. They require a sequence of miracles to come true.
We’ve known these things for a long time. Nothing has changed, really. Renewable electricity is more available, popular, and cheaper than ever. But nothing about hydrogen has changed. 120 megatonnes of the stuff was made last year, and 98.5% of it was made from fossils, without carbon capture. It’s a technical gas, used as a chemical reagent. It is not used as a fuel or energy carrier right now, at all. And that’s for good reasons associated with economics that come right from the basic thermodynamics.
What we have is interested parties muddying the waters, selling governments a bill of goods- and believe me, those parties intend to issue an invoice when that bill of goods has been sold! And that’s leading us toward an end that I think is absolutely the wrong way to go: it’s leading us toward a re-creation of the fossil fuel paradigm, selling us a fossil fuel with a thick obscuring coat of greenwash. That’s not in the interest of solving the crushing problem of anthropogenic global warming:
We need to solve the decarbonization problem OF hydrogen, first. Hydrogen is a valuable (120 million tonne per year) commodity CHEMICAL – a valuable reducing agent and feedstock to innumerable processes- most notably ammonia as already mentioned. That’s a 40 million tonne market, essential for human life, almost entirely supplied by BLACK hydrogen right now. Fix those problems FIRST, before dreaming of having any excess to waste as an inefficient, ineffective heating or comfort fuel!!!
Here’s my version of @Michael Liebreich’s hydrogen merit order ladder. I’ve added coloured circles to the applications where I think there are better solutions THAN hydrogen. Only the ones in black make sense to me in terms of long-term decarbonization, assuming we solve the problem OF hydrogen by finding ways to afford to not make it from methane or coal with CO2 emissions to the atmosphere- virtually the only way we actually make hydrogen today.
If Not Hydrogen, Then What?
Here’s my suite of solutions. The only use I have for green hydrogen is as a replacement for black hydrogen- very important so we can keep eating.
There are a few uses for H2 to replace difficult industrial applications too. Reducing iron ore to iron metal is one example- it is already a significant user of hydrogen and more projects are being planned and piloted as we speak. But there, hydrogen is not being used as a fuel per se- it is being used as a chemical reducing agent to replace carbon monoxide made from coal coke. The reaction between iron oxide and hydrogen is actually slightly endothermic. The heat can be supplied with electricity- in fact arc furnaces are already widely used to make steel from steel scrap.
In summary: the hydrogen economy is a bill of goods, being sold to you. You may not see the invoice for that bill of goods, but the fossil fuel industry has it ready and waiting for you, or your government, to pay it- once you’ve taken the green hydrogen bait.
DISCLAIMER: everything I say here, and in each of these articles, is my own opinion. I come by it honestly, after having worked with and made hydrogen and syngas for 30 yrs. If I’ve said something in error, please by all means correct me! Point out why what I’ve said is wrong, with references, and I’ll happily correct it. If you disagree with me, disagree with me in the comments and we’ll have a lively discussion- but go ad hominem and I’ll block you.
