Can China Make Hydrogen Electrolyzers Cheap as It Did for Solar?

I read that a smallish, but not tiny, house needs about 500 gallons of propane to go through a winter. Yours will need more or less, but let's work with this. Propane has a pretty low density of about 0.5 g/cm3, so 500 gallons work out to be about 1000 kg. Hydrogen has more than twice the energy density of propane. Moreover, you'd probably use hydrogen to generate electricity via fuel cells, rather than to burn it like you burn propane. Heating via electricity and heat pumps is at least twice as efficient as via a furnace with propane, so let's say you need about 250 kg of Hydrogen.

It's difficult to find prices of large hydrogen tanks online, everyone puts a button with "Call for quote". But I found a study by the DoE [1] where it appears that the bulk cost for large hydrogen tanks of type IV that can hold 220 kg is about $75k. The best tanks are type III which have virtually zero leakage rate. I imagine those are more expensive. Type IV have some leakage rate, which should be proportional to the surface area of the tank. Because of the square-cube law, very large tanks like this one should have a lower leakage rate than smaller tanks like those used in a Toyota Mirai (which can hold only about 5kg of H2). Overall, I think you could expect less than 10% losses, maybe much less.

Of course, you'd need to add the cost of the electrolyzer, of the fuel cells, of the heat pumps etc. It looks quite expensive to me, but lots of things related to home improvement are expensive. This one, you actually get (some of) your money back in time.

[1] https://www.hydrogen.energy.gov/docs/hydrogenprogramlibrarie...