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Comment by asgeirn | Hacker News Reader

Most counterarguments related to Hydrogen refer to the poor efficiency of converting (electric) energy to Hydrogen and back.

True, directly using that electric energy from wind or solar is definitely the best option.

However, that is not always possible, since there is no place to consume, transport or store that electric energy.

Furthermore, scrapping all ICE vehicles for BEVs is most likely the end goal. But replacing the worldwide fleet of vehicles will take decades.

HyTech seems to be on to something for these two scenarios.

If for instance you can capture some of the excess solar and wind energy in a metal hydride for some hours, weeks, or even months, you will on a larger scale reduce the load of the electric grid.

And if some of that Hydrogen can be burnt instead of Diesel, the car or truck in your driveway is both cleaner and less dependant on fossil fuels.

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I really don't understand why the debate on H2 is so focused on electrolysis. Even today, 95% of all hydrogen is produced not by electrolysis, but from natural gas through steam methane reforming (SMR).

SMRs can be easily scaled up to meet all H2 demand, and they are easily fitted with carbon capture technology (since it's a single large emission point). Then you have zero-emission H2 in quantities as large as oil and gas today.

I'm entirely convinced it will be the future, and that we'll never be able to scale pure BEVs beyond 10-15% of all cars in any large country, simply due to electricity production and distribution constraints.

The problem with nifty solutions to removing carbon from raw fuels resulting in carbon free hydrogen, is the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons to make some delicious hyper optimized liquid fuels, which coincidentally we have massive infrastructure to use.

Not as snarky as might sound. Given infinite fusion energy via the real thing or solar panels, truly pure synthetic fuel opens up some interesting ideas WRT catalysts and efficient burn designs to squeek out another percent or two of performance. Inherently zero (not low, but ZERO) sulfur diesel is interesting, for example. And no one says the carbon thats added has to come from underground; go harvest some trees that sucked the carbon right out of the air, then when you put it back in the air after a couple months of storage, nothing bad happened.

You can burn anhydrous ammonia in a regular ICE. If we adopt GP's hypothesis that energy is cheap, then it's also cheap to turn H2 into NH3. We already have a robust infrastructure for the manufacture, storage, and transportation of liquid anhydrous ammonia. It does present some dangers to human safety, but so does any fuel.

If cars ever run on hydrogen in significant numbers, they'll actually be running on ammonia.

> the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons

If that's the case, it's equally true for H2 from renewables, no?

And I don't think it's true. LPG vehicles today are common enough, and they've solved very similar transport and distribution problems.

Not really. Hydrocarbons are much easier to store and handle. Cars may not need it so much, but as a jet fuel, kerosene is much easier than hydrogen.

Easier, sure. But Tupolev built and flew 100 flights with the Tu-155, a cryogenic H2 fueled narrow-body airliner, in the 1980s. So it's very far from impossible, it's just a matter of time IMO. Currently aviation is pushing biofuels to kick the can down the road, but they can't do that forever.

And you can easily use that extra carbon for growing plants in vertical farms next to the SMR plant.

Would impurities in the source methane be a problem for this case?

For a hydrogen based infrastructure we need 3x as much electricity than for one which directly uses electricity via batteries. You cannot use hydrogen in cars already built - unless you want to sacrifice your rear passenger row for an add-on tank (H2-tanks are quite bulky). So it is new cars anyway. Making them directly electric is the way more efficient way.

If you have excess electric capacity, I think there are more convenient things to produce, such as aluminum. It lasts forever, it's easy to transport, producing it is very energy-intensive, and there's a constant demand. E.g., aluminum is a big industry in Iceland thanks to its cheap geothermal/hydro energy.

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