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Comment by darksaints | Hacker News Reader

This is by far the dumbest take I've ever seen on the matter. No, people aren't obsessed with hydrogen because they can fill up in 5 minutes, because for the vast majority of car buyers, charging at home is an even better idea. Hydrogen cars are unlikely to ever take hold outside of maybe the taxi market, which is why so few automakers are investing in them. But there is a massively promising market for hydrogen trucks and other long haul transport. There is a reason why the company that actually released the first electric truck has invested billions more in hydrogen research.

It's all about the energy density.

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I constantly see people say they won't buy an EV because of recharge times and not being able to go on a 'road trip'. There seems to be some misunderstanding about how easy it will be to add hydrogen filling stations vs charging stations. While I don't know the % of people that actually care about charge/filling times, there are always some comments. I mean, I know someone in real life that says that, or at least did, and could certainly afford a Tesla, but still chooses a gas vehicle.

Now, will they eventually come around? Maybe, but a refillable combustion engine burning hydrogen certainly has some marketability, and perhaps some companies (like Toyota) made a miscalculation on how easy it would be to get people into EVs vs actually developing Hydrogen vehicles. I have a hard time understanding why Toyota has so little in EV offerings if this is not the case (and Toyota's advertising in Japan still doesn't mention full EV as the future).

Methanol powered fuel cell electric vehicles FCEV appear very promising to me.

Filling up methanol is much more convenient than hydrogen or charging a BEV.

The hurdles are of course that fuel cells are more complex and apparently not yet reliable and cheap enough to compete with batteries.

Also, the overall energy efficiency of FCEV will obviously never be on par with BEV.

My belief is that if enough big players in the truck/car/... industry invest heavily in advancing fuel cell technology ... then the huge advantage of ease/convenience of use (and also the independance from electrical grid) will make FCEV the most used tech in the long term.

> It's all about the energy density.

Which is why I'd bet on methanol rather than hydrogen.

Methanol is a good choice for the situations where hydrogen is unwieldy or impractical. Ive actually played with it a bit...far easier to synthesize than other hydrocarbons, and it works quite well as a direct fuel for solid oxide fuel cells. But per weight it has a much lower energy density than hydrogen. It matters more than you'd think...in the 80s methanol was tried by a lot of trucking companies, which eventually came to the conclusion that the energy density was too low to make sense. The weight of the extra fuel ended up costing them more because they couldn't haul as much, despite the methanol being a bit cheaper. Of course the fuel price economics are quite a bit different now, and that may change, but the point is that energy density by weight matters a lot.

And I think you'd be surprised at how practical hydrogen can be for some use cases. Aircraft, for example, likely wouldn't even need cryogenic storage for liquid hydrogen because consumption rates are higher than evaporation rates even with basic foam insulation. And hydrogen pressure vessels are now getting to the point where they're feasible for trucks.

> But per weight it has a much lower energy density than hydrogen. It matters more than you'd think..

I highly doubt that energy density in respect to weight is in the top five of issues that stand in the way of widespread adoption of methanol as a fuel for FCEV.

I don't have any numbers on my hands on this. But even if you take into account the complete chain of energy transfer from storage to wheel (where a fuel cell adds inefficiency compared to BEV), then I'd guess a battery holding the same amount of mileage would weigh a multitude of the fuel cell and methanol tank system.

> ... in the 80s methanol was tried by a lot of trucking companies, which eventually came to the conclusion that the energy density was too low to make sense.

Well, back then the methanol was obviously compared to diesel/gasoline, not to batteries in an electric vehicle. Of course methanol can't compete with the former two, but since these are to be replaced, they're not the benchmark here, right?

> ... energy density by weight matters a lot.

I'm pretty sure that energy density by volume matters far more than by weight. Otherwise there'd be no issue just storing hydrogen at room temperature at low pressures such as 10 bars ... but then you'd probably pull another TEU behind the truck just for the low pressure hydrogen.

> Aircraft, for example, likely wouldn't even need cryogenic storage for liquid hydrogen because consumption rates are higher than evaporation rates even with basic foam insulation. And hydrogen pressure vessels are now getting to the point where they're feasible for trucks.

Sounds like a valid point. But doesn't this neglect the whole infrastructure _before_ the hydrogen reaches the vehicle/aircraft/whatever? Methanol could be easily pumped into/out of an existing tanker/tank and shipped around the whole world without time pressure ... or pumped through some pipeline ... it's low tech. I'll be surprised if we ever see a significant proportion of chemically stored energy being transported intracontinentally in the form of hydrogen.

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