Comment by pineaux | Hacker News Reader

Comment by pineaux | Hacker News Reader

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This sounds logical, until you find out that the only viable way (make H2 from electrolysis) is wildly inefficient (75% efficiënt), then compressing/chilling it for transport is only (90%) efficiënt, then converting it to electricity with a fuel cell (max 60% efficiënt), followed by powering an electric motor (95% efficiency).

This adds up to: 0.750.90.6*0.95=38% efficiency.

With an electric battery car. Its about 75-80% efficiënt in the whole chain. That means you need twice as many wind turbines to run the same amount of vehicle miles. The math just doesnt hold up.

So unless we cannot produce enough batteries or cannot make the grid stronger. Which both are possibilities. Hydrogen cars will probably be a dream. At this point it just doesnt make sense.

Electrolysis is theoretically up to 100% efficient. So are fuel cells. The whole process is an electrochemical system not much different than what batteries are.

You're reading too much pro-BEV propaganda. They're just spreading FUD and trying to stop people from realizing there are alternatives.

That’s great, but in the real world we care about the actual efficiency.

It is not FUD or propaganda to say that the fuel cell cars you can buy today (or in the next 10 years) are not even close to 100% efficient. Nor is their round trip efficiency better than BEV. Nor or either of those numbers likely to change over that period.

If you cared about actual efficiency, you'd be skeptical of BEVs today. There's no straightforward of powering them directly with renewable energy. You will need vast amounts of energy storage to make that work. That will not be all that efficient. And that's after you accept the huge upfront cost of the batteries and all the problems they entail.

Meanwhile, no one is looking at compromise solutions. Something like a PHEV or even a plug-in FCEV would solve a lot of these complaints right away. There are ways around these issues even in the real world.

Finally, it's not like 10 years is that long in the car industry. If FCEVs end up matching BEVs in efficiency in 10 years, that's means we're pretty much at the verge of FCEVs taking over.

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