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Comment by helterskelter | Hacker News Reader

I always figured it would make more sense for hydrogen to be an option for renewable infra if the problems with leaking and embrittlement could be solved. Currently, moving renewable power over very long distances and storing it at scale is a non-trivial issue which hydrogen could help solve.

This way, for example, Alaska in the winter could conceivably get solar power from panels in Arizona.

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These problems are grossly exaggerated in popular discussions. Hydrogen has been routinely transported and stored in standard steel cylinders for over a century. Most cities originally used coal gas (50% hydrogen by volume) for heating and illumination before switching to natural gas after World War II. What kills the idea is the abysmal efficiency of electrolysis and hydrogen fuel cells. Standard high-voltage DC power lines would be much better suited for getting solar power from Arizona to Alaska.

Storage is the bigger problem, specifically very long duration or rarely used storage (to cover Dunkelflauten, for example) for which batteries are poorly suited. Hydrogen (or more generally e-fuels) is one way to do that, but another very attractive one is very low capex thermal storage. Personally, I feel the latter would beat hydrogen: the round trip efficiency is similar or better, the complexity is very low, power-related capex should be lower, and there's no need for possibly locally unavailable geology (salt formations) for hydrogen storage.

With this sort of storage, Alaska in winter gets its energy from Alaska in summer.

Moving renewable power is easy, we have a grid for that. Infrastructure for movement of electricity is ubiquitous in places that have never seen a hydrogen pump.

If the grid is insufficient in a particular place or corridor, investing in upgrading it will provide a better long term solution than converting electricity to hydrogen, driving that hydrogen around on roads, and converting it back into electricity.

Storage is a bigger issue for sure.

Only if we had a true oversupply of green energy. Converting electricity to H2 and then back is so incredible inefficient. It's less work to just create better electrical transmission systems. China did that with their high voltage DC lines.

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