Here a few major issues hydrogen would need to solve.
* There isn't a fuel distribution system. The reason BEVs work is because everywhere has power, setting up power distribution is generally just plugging into the local grid.
* Hydrogen escapes any container it's placed in. That's a pretty hard thing to deal with. Most approaches have looked at chemically binding hydrogen to something in order to keep it from escaping, but that, as you can imagine, is expensive. The other option is onsite electrolysis, but that's rather expensive to pull off.
* Speaking of electrolysis, while we can get hydrogen from many sources, the one we are likely to actually use isn't electrolysis but rather natural gas and oil. Why is that? Because electrolysis is inefficient (about 20% efficiency IIRC edit I recalled incorrectly. Electrolysis has a ~70% effciency).
So you have a hard to store fuel, without a distribution network, that may be coming from fossil fuels anyways. -So why do major companies like Toyota love hydrogen? Because it doesn't require them to make any major changes to their fleet. You can get a lot more miles out of the basic combustion engine design and you don't need to retool all your product lines.- edit I was wrong, looks like most hydrogen vehicles are fuel cell based.
Now, that isn't to say that hydrogen has no place in the future. I think because of it's energy density hydrogen will likely play a role in the airline industry. It may even be possible that hydrogen ends up finding a place in long range shipping. However, hydrogen in a consumer car is, IMO, DOA. BEVs already exist as do their charge networks.
Actually it's pretty efficient. According to wikipedia, efficiency ranges from 70% for the cheaper method, to 80% with more expensive catalysts. Theoretical efficiency is 94%.
It's all of the other required bits that makes Hydrogen so inefficient. Transportation, building up pressure, etc. Hydrogen if you compare things simply is more efficient than gas/diesel. However, gas/diesel is pumped out of the ground. Meaning, a lot of the energy needs for gas/diesel are already there.
I was only commenting on electrolysis, I did not make any statement about hydrogen power in general. However, now that you brought it up, the other issues that you mention are very surmountable:
- Transport. You can either transport hydrogen via pipelines or simply produce it via electrolysis in-place. You have to get the electricity to the destination somehow, so this doesn't really differ between electric and hydrogen cars.
- Building up pressure. Energy required to build up pressure is related to how much the volume is reduced (force x distance and all that...) Conveniently water is almost incompressible, so you can raise the water to the desired pressure cheaply before you electrolyse it. https://en.wikipedia.org/wiki/High-pressure_electrolysis says this can be done at 97% efficiency.
well theoretical efficiency can never be achived, also it might be more efficient than gasoline cars it can never be more efficient than BEV, because you need to convert power into hydrogen and back, converting anything always has losses
> You can get a lot more miles out of the basic combustion engine design
Why would there be a combustion engine in a hydrogen car? I expect that there would be a fuel cell powering electric motors. Are there other ways to use hydrogen in cars, other than fuel cell? I'm not an expert.
Doesn't look like a great path forward - deep internal engine parts need to be modified (no "hydrogen kit" for existing cars), they emit NOx emissions (so not zero-emission), and you have all the disadvantages of a combustion engine.
However, combustion engines have 100 years of development behind them and a proven track record of reliability (probably billions of running hours by now). Fuel cells are still newish - "the devil you know". This would also keep mechanics employed and keep dealership service bays busy... kind of a perverse incentive, but it's there for sure.
It may be a stop-gap, or useful for certain situations (long haul trucking is mentioned). It could be part of the tapestry of technologies needed to move to a more renewable-based future.
* There isn't a fuel distribution system. The reason BEVs work is because everywhere has power, setting up power distribution is generally just plugging into the local grid.
* Hydrogen escapes any container it's placed in. That's a pretty hard thing to deal with. Most approaches have looked at chemically binding hydrogen to something in order to keep it from escaping, but that, as you can imagine, is expensive. The other option is onsite electrolysis, but that's rather expensive to pull off.
* Speaking of electrolysis, while we can get hydrogen from many sources, the one we are likely to actually use isn't electrolysis but rather natural gas and oil. Why is that? Because electrolysis is inefficient (about 20% efficiency IIRC edit I recalled incorrectly. Electrolysis has a ~70% effciency).
So you have a hard to store fuel, without a distribution network, that may be coming from fossil fuels anyways. -So why do major companies like Toyota love hydrogen? Because it doesn't require them to make any major changes to their fleet. You can get a lot more miles out of the basic combustion engine design and you don't need to retool all your product lines.- edit I was wrong, looks like most hydrogen vehicles are fuel cell based.
Now, that isn't to say that hydrogen has no place in the future. I think because of it's energy density hydrogen will likely play a role in the airline industry. It may even be possible that hydrogen ends up finding a place in long range shipping. However, hydrogen in a consumer car is, IMO, DOA. BEVs already exist as do their charge networks.