This is the second in a short series of articles that will culminate on Halloween, in which we present four zombie technologies that display zombie characteristics
We’ve all seen it: great new technologies with huge potential from a central promise to revolutionize what we do. However, each comes with a challenging list of problems that — when viewed objectively — relegate the technology to prototype form with limited commercial value. These problems could include available technology, cost, business model, and in some cases, the basic laws of physics.
However, these problems aren’t enough to stop hardy groups of individuals from continuing their development and promotion, fuelled by the promise of fulfilling those technologies’ potential.
New Mobility is no exception. In this short series of Halloween-themed articles, James Carter and Paul Martin analyze four technologies that display zombie characteristics.
Zombie Technology 1: Solar panels on cars
Zombie Technology 2: Hydrogen fuel cell cars
Zombie Technology 3: Wireless charging
Zombie Technology 4: E-roads
Zombie Technology 2: Hydrogen fuel cell cars
The dream
Emissions-free driving, using a fuel made from water using excess solar and wind electricity. We refuel in minutes at a “gas station” just like we do today, with a range per fill about the same as a typical gas engine car. What’s not to like?
How it works
The H2 (hydrogen molecule) dream being pitched is that we soon will make renewable electricity in abundance — way more of it during parts of the day than we need. We could use that excess to generate hydrogen from water at a fuelling station. The hydrogen will be stored onboard the vehicle as a high-pressure gas, which is fed to a fuel cell — a type of flow battery where hydrogen reacts with oxygen from the air, with the resulting flow of electrons being used to run an electric motor.
Why it should die (or how it could live)
The idea is a seductive one and has received a great deal of support from Asian OEMs such as Toyota, Honda and Hyundai. But sadly, the devil is in the details.
Today, hydrogen is used in massive quantities around the world as an industrial gas, and 96% of it is made from fossil fuels, with consequent CO2 and other emissions entering the atmosphere. The hydrogen process involves three steps: making hydrogen, storing and distributing it, then producing electricity again in a fuel cell. Each step loses energy — and not just a little. Best-case efficiencies are approximately 70% for electrolysis (separating water into hydrogen and oxygen), 90% for high-pressure storage, and 60% for the fuel cell. For every kWh fed to the electrolyzer, just 0.37 kWh (or less) comes back out of the fuel cell. Thus, through this process, most of the energy is lost. In contrast, a lithium ion vehicle battery gives back about 90% of the electricity it is fed. Those H2 limits are mostly thermodynamic, or natural laws of physics, so we’re unlikely to see significant improvements with new inventions. Energy is never free, and always comes with an environmental impact. Hydrogen’s inefficiency makes it a very expensive fuel in terms of both cost and the environment.
Hydrogen also takes up a lot of space. Even at 10,000 psig (pounds per square inch, gauge) — 700 times the pressure of the atmosphere — hydrogen is still only 42 kg/m3. That low density makes it hard and expensive to store and distribute. The hazards of a flammable, high pressure gas mean that refuelling must be tightly controlled, eliminating any ability to refuel at home, like you would for an electric vehicle.
Then there’s the vehicle. A fuel-cell car contains every part that an EV contains — including a smaller EV battery — plus the fuel cell and hydrogen systems.
The problems with hydrogen as a vehicle fuel become most stark when you compare two cars you can buy today: the Toyota Mirai FCEV and the Tesla Model 3 long range BEV. While both cars have roughly a 300-mile (500 kilometre) range, the Mirai is heavier, more expensive, much slower, uses 3.2 times as much energy per mile and costs at least 5.4 times as much per mile driven. This calculation is done where the hydrogen used is only one-third renewable and two-thirds cheaper fossil-sourced hydrogen. That’s a very hefty price to pay for faster refuelling — assuming there’s a hydrogen station along your route (a very big “if”).
Clearly H2’s potential for vehicles and most land-based transportation is limited. However, due to hydrogen’s energy density advantages over lithium ion batteries when used for long distances, there may be potential for usage in long range transportation, such as trains, shipping and possibly ultra-long-haul trucking.
Today, less than 1% of hydrogen is made from renewable resources, and the excess renewable hydrogen that people think we’ll be fuelling their cars with, just doesn’t exist — and will not exist until a significant and sustained carbon tax is applied. Even if we do see lots of hydrogen being generated one day from renewable electricity, directly using that electricity in an EV instead will still have a huge cost advantage. That advantage arises from basic physics and chemistry, which is why the H2 dream will continue to struggle.
Our Halloween conclusion
H2 has some potential narrow use cases for long-distance transportation, but it’s a waste of time for your car.
In this series
Zombie Technology 1: Solar panels on cars
Zombie Technology 2: Hydrogen fuel cell cars
Zombie Technology 3: Wireless charging
Zombie Technology 4: E-roads
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Paul Martin is a chemical engineer, and lifelong environmentalist. He’s a passionate advocate for electric vehicles (he built one himself), and a renewable energy advocate. He has spent 23 years at Zeton Inc. designing and building pilot and demonstration plants for the chemical process industry, helping clients bring new chemical process technology to market.
7 comments
As someone once told me, “hydrogen, it’s great in PowerPoint, but it’s rubbish in Excel”
Absolutely correct- I love the comment!
Any observations on not so recent reports of H2 from a process of water reacting with ‘Nano Aluminium particles’ (whatever they are!). This came about as a side reaction to work being done by the US military and some companies (Shell May be one of them) are ‘taking an interest. Apparently the creation of H2 using this method is pretty efficient. Note: I am not a chemist!
Sadly, you’ve got this wrong. NIce tag line, just absolutely no thought whatsoever about the subject material.
First of all, electrolyser efficiencies are now 80%. They also produce hydrogen at pressure, reducing the energy required for compression. New designs are producing hydrogen at 96% efficiency for specific periods.
Hydrogen can be produced for the same cost as gasoline using wind and solar today, although it will be some time before these costs are delivered to customers. There is also massive scope for cost reductions, with various analyses citing a sub-$1.50 per kg price by 2030.
The issue with battery electric cars is that the energy doesn’t magically get transported precisely when its created, at all times. Therefore some form of storage might be necessary. Just a few pointers.
Daniel Williams: “electrolyzer efficiencies are now over 80%”. Sure- if you base the efficiency on the HHV of the product hydrogen, 80% is a good number- from a very expensive low current density PEM electrolyzer. Make it economical by increasing the current density by a factor of two and the efficiency drops to 70% or even lower. And when you make the comparison on the basis that is fair, the LHV of hydrogen, the efficiency of 83% you’re talking about on a HHV basis drops to 70% on an LHV basis. That matches with the 60% LHV efficiency (again for an expensive low current density) PEM fuelcell. So my calculations are actually based on very much best case figures in the efficiency chain for hydrogen.
People make all sorts of claims. I’d put that claim of $1.50/kg for green H2 in 2030 up there with the claim that we’ll be below $100/kWh at the pack level for Li ion EV packs by 2030. Easy to say, but based more on hype and wishful thinking than on any sound economics.
Grid losses from plant gate to meter are around 5% on average in the US. Here in Toronto the loss is about 3%- check your Toronto Hydro bill, as you pay for that loss which is stated right on your bill. So sure, power is made in a different place than it is used. But electricity can be distributed quite efficiently. Not hydrogen though- its low density means that it’s a bastard to transport, and that results in the fact that every major hydrogen user has their own hydrogen plant or is built across the fence from an existing one. There are a few hydrogen pipelines in a few “chemical valley” type settings but they’re at most 100 miles in length. Most of the H2 refuelling stations built out in the world are using the least efficient mode of transport- tube trailers- to keep the cost of the fuelling stations low. The efficiency of moving hydrogen by tube trailer is positively pathetic- not even worth discussing as it isn’t a long term strategy that anyone is pursuing. Instead, they plan to move something else- electricity or methane- to where the hydrogen is needed.
As to the need to store renewable electricity- that’s obvious. EV batteries opportunity charged while the vehicles are parked at work is an obvious way to store some of that energy with high efficiency. What is also obvious is that although it is technically possible to use hydrogen as that means of storage, it isn’t economically feasible without very significant carbon taxes. That, fundamentally, is why hydrogen is 96% made from fossils without carbon capture at present.
More detail on that in this article:
https://www.linkedin.com/pulse/hydrogen-from-renewable-electricity-our-future-paul-martin/
This EA Canada piece was a nice fun short piece with less of a technical focus,, but my LinkedIn articles give more detail if you’re interested:
https://www.linkedin.com/pulse/hydrogen-fuelcell-vehicle-great-idea-theory-paul-martin/
Your claim of 96% efficiency is for a high temperature steam electrolyzer and plays a similar sleight of hand by ignoring the energy to boil and preheat the feed steam. Steam electrolyzers are basically SOFCs run backwards and they generate hot H2 and O2- sometimes useful, but not for storage for sure.
A real problem for H2 is the lack of investors willing to put money into infrastructure development at scale. Key H2 OEMs won’t touch it with a barge pole, yet Tesla proved that if you want an alternate energy vehicle to succeed, you must provide the infrastructure (noting that most BEV buyers also have at home / work energy provision) Even if all the problems discussed in the article are solved, lack of support at scale for infrastructure will stop H2 dead.
@James: the stuff you’re referring to is “alane”, which is aluminum hydride. It is a military source of hydrogen- which requires a high pressure high temperature process plus an aluminum refinery to “recharge” it. It’s akin to running an EV on a nonrechargeable zinc-air battery such as the one used for hearing aids. It’s possible, and might make sense when cost is no object- but it certainly is not an efficient mode of transport.
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