Hydrogen is not the future, it will never be the future and here's why.
Every week or so someone writes about how they're "waiting for Hydrogen cars" or how we only need battery cars until hydrogen is "ready for primetime"
It makes me want to spit and write 10,000 words in the comments, so to save time and phlegm here's my definitive takedown so I can link to it in future.
EFFICIENCY
Lets start with the basics: Hydrogen is not a "Fuel" like gasoline but rather a method of electricity transmission.
Once we get away from oil/gas which is essentially "free" energy gushing out of the ground then we have to generate it. Whether that's through solar/hydro/wind or "burning" nuclear isotopes in a reactor it all starts as electricity.
We're all familiar with the classic hydrogen cycle: split Hydrogen (H2) from water (H2O)with electricity, transport the hydrogen to the gas station, pump it into your car, power the car using a hydrogen fuel cell and electric motor and the car's only emission is nice clean water.
It makes for a lovely elementary school science fair diorama but in reality is a complete crock of shit because of the process losses are ridiculous.
You can skip the next 4 paragraphs if you read this diagram - its from Ulf Bossel's excellent analysis from 2006 and nothing has really changed except batteries got waaaay cheaper
First job is to split hydrogen from water molecules using electrolysis, this is requires converting AC power to DC (-5%) and then electrolysis is not very efficient: about 20% of the energy is lost in conversion.
So say we start with 100 units of electricity only 75 remain after we make the hydrogen.
Fun sidebar its way cheaper to strip hydrogen off methane with steam than using electrolysis so that's how 95% of it is produced at the moment. Guess what the byproduct of that reaction is? - yup CO2. Just burn the damn natural gas already.
Next you need to pack down the least dense element in the universe small enough to make it transportable without using a Zeppelin. You can either compress it real hard or liquify it by chilling to –253 ºC (–423 ºF). This uses a boatload of energy but doesn't add any value to your fuel; cool, coolcoolcoolcool.
Liquified hydrogen also boils off and has to be vented as it warms up in the tanks, the longer you store it the more you lose.
Then you drive it to a gas station in a tanker truck which uses energy to move and more to transfer the hydrogen in and out. The net effect is by the time it reaches your car only 40-50% of the generated energy remains.
Now we get to the easy part; run it through a Hydrogen fuel cell to generate electricity, this is about 50% efficient so now 20-25 units of energy remain
Then we have the electrical drive system and motors which are about 90% efficient - not too bad.
So the end result: only 19-23 units out of 100 that you paid to generate actually provide any motion to the wheels.
This is -in short- godawful, it's pissing ~80% of the energy you paid for up the wall in system losses.
Let compare with an existing battery electric car. Grid transmission is about 90% efficient, AC/DC conversion plus battery charging 85% and the same 90% for the electric drivetrain.
End result about 69 units out of 100 make it to the wheels.
But but but but people may say: these processes will improve with future technology like fluidized bed catalysts, nanotube electrodes, flux capacitors and midichlorians…. but let's be real, it's polishing a turd.
Most of the losses come from established "Cannae change the laws of physics" stuff like trying to compress a stupidly light gas molecule and move it cross country. The diagram above is from 2006 paper and the math isn't appreciably different in 2022.
Wasting more than twice as much energy as an established technology is not a position you can stage a comeback from.
INFRASTRUCTURE
But we haven't even got to the really big road block yet: the infrastructure.
So the hydrogen fuel tanks in the Honda clarity run at 70 MPa or 10,000psi that is ludicrously, terrifyingly fricking high pressure and requires some serious engineering to handle.
For context most car tires run around 30-35psi and the tank for your BBQ is 100-200psi (propane is actually liquid when compressed to that pressure because it's a bigger hydrocarbon molecule).
The general public who smoke around gas pumps and drive off with the hose still attached have no business being near 10,000psi of stored energy.
But lets ignore the issues with spontaneous pyrotechnics for a moment.
There is no way to refuel Hydrogen cars except at a dedicated filling station; assuming range and refuel time is similar to gasoline we need to replace every single gas station that currently exists: there were 115 thousand of the them and climbing in the US in 2017 (the year I could get data). Hydrogen stations are running between $1-2M just for the equipment.
Charitably assuming $1M per station cos it makes the math easier that's 115 Billion dollars just at the retail end. That might not be too much in defence procurement circles but ask your local dingy, minimum wage employing filling station if they've got a spare mil lying around.
Or y'know I could just:
As of January 2021, there were 45 publicly accessible hydrogen refueling stations in the USA, 43 of which were located in California and nobody is rushing out to build hundreds of thousands more.
One more time: 115,000+ vs 45
Honestly the filling stations are the cheap bit; we'd need a fleet of special tankers to supply them, massive refrigeration/compression plants to chill/compress the hydrogen and industrial electrolysis plants to generate it - nationwide. None of this exists, none of it is easy and all of it is incomprehensively expensive. Plants are going to be in the hundreds of millions and we are going to need a lot of them: think replacing every oil refinery in the country.
Plus the electricity grid is going to need to the scaled up; my napkin math suggests 20-40% more electricity generation will be needed for EVs eventually but given the wastage with hydrogen you'd have to at least double the current national generation capacity.
WATER
Electrolysis to produce hydrogen will need to use drinking quality or maybe cleaner water, since any impurities are going to foul the electrodes.
How are we doing for fresh water worldwide at the moment? Got lots of it to spare? No didn't think so
A fuel cell car produces about 0.15kg of water per mile so using our 3.2 trillion miles a year number (3.2x0.15=0.48) that's nearly half a trillion, or 480 billion litres of drinking quality water. Which is in a similar ballpark to the 559 billion litres of gasoline America used in 2020.
The average person drinks 1-2L of water per day, take the average and multiply by the population of the USA ~334 million.
334x1.5x365=182,865 million or 182.8 billion litres.
That means our cars will drink more than two and a half times what we currently do.
This has danger and future roller skating dystopia written all over it - especially when some cities already have difficulty not poisoning their population.
(I appreciate other household, farming and industrial uses of water dwarf drinking water but let's focus on staying alive here)
Remember when we tried burning food in cars (E10/E85 ethanol) it drove the prices of corn and other staples up. Let's not do that with water.
DUDE WHY?
Why are we doing all this again? Oh right to save half an hour or so in refuelling time over batteries.
Its worth noting carmakers are talking about 1,000km range EVs now and as that battery gets bigger the inrushing charge gets spread out amongst more cells. This means you can push a more energy in faster without overheating and get a useful amount of distance loaded up quicker.
Mercedes state their new EV will be able to recharge 300 km (174-186 miles) of range in 15 minutes
EVs still have some challenges for sure but they seem surmountable (that's a whole other article). The problems with Hydrogen make it straight up impossible.
Sure there may be a few niche applications but I'm still skeptical the economics will work out for cost sensitive industries like trucking, rail, shipping or aviation either.
This gigantic pile of stoopid is why I get angry every time someone even mentions hydrogen cars.
There is no.frickin.way. economically, practically or environmentally.
Maybe 30 years ago there was a debate about what the future held but now it's quite clear batteries work ok but Hydrogen never will. They are competing technologies too, nobody is going to build trillions in hydrogen infrastructure just to get their ass kicked.
So next time you see someone who is pushing hydrogen look for their agenda, they're either:
• Trying to con investors (Nikola)
• Divert time and money that could be better spent elsewhere (any oil co.)
• Have lingering misguided funding/tax credits left to milk (some universities/govts)
• Have sunk so much money into it they can't admit they're wrong (Toyota - until shockingly recently)
• Lazy auto journalists who haven't kept up (also won't have bothered to read this far)
The oil companies like hydrogen because it looks like their current business model: pushing chemical energy around in pipes and tankers. Cynically I think they like it even more because they're fully aware it's infeasible; if you could pick the competitor to eventually drive you out of business wouldn't you pick the lame dead duck?
TLDR
So in short the Hydrogen future requires us to:
• Double our generation capacity but make electricity so cheap we can afford to waste over three quarters of it in process losses.
• Have so much available fresh drinking water we're ok burning it like gasoline.
• Build more untried infrastructure at once than anyone ever has in history that will never make any money.
• Do it all quickly enough to stop the planet from warming irreversibly and killing us all.
If you think there's something wrong with this assessment I'd love to hear why, but bear in mind "In god we trust, all others bring data"
to some degree at my current company but there are still days they have to cut production.
