That is one of the least efficient solutions possible - making hydrogen gas from water is at best 50% efficiency, and then you get to burn that hydrogen in a thermal engine with 30% efficiency.
This is the problem with the anti-h2 crowd. It's almost all based upon lack of understanding.
One person in this thread, was talking about cars, with no knowledge or understand that 3 separate manufacturers have h2 products on the market. Not 3 cars. 3 manufacturers. Another was discussing things as if it's an insurmountable task, that having h2 in cars is "really hard", yet these cars are being sold and used all over the world, with loads of adoption in Japan.
People make up weird claims about efficiency. About storage. About where h2 comes from. On and on and on. It's so ... absurd.
This isn't a 'my team your team' thing, yet it seems like, especially americans, are wired this way. "It's not thing $x, thus evil! wrong!! We must, absolutely must destroy any hope of this other thing existing.
h2 is the future for many application and usage spaces, and I can see batteries the same way too. It's not either or, and made up claims won't help the green movement at all.
They're a maximum 85% efficiency, with a range of 40-60%, and then you're supplying electricity to a 90% efficiency electric motor. So, overall, you have 90% of 85% of 50% of the generated electricity going into moving your car, so at best around 38.5%.
In contrast, an electric car uses electricity to charge a 99% efficient battery, and discharge to the 90% engine. So, 89% efficiency - much, much better.
