Could residential hydrogen generation, storage, and use be viable? Say you have solar, a water supply, and a big hydrogen tank. Any excess electricity can make hydrogen by electrolysis and store it to be used for heating and cooking. No expensive transport or exotic fuel cells. In arid climates the water vapor from burning it could even be captured.
The two big problems I see are that hydrogen is trickier to pipe than natural gas, and if there is no hydrogen economy to make backup deliveries, how do you keep up with essential heating when there isn't much excess electricity?
Residential anything will scale worse than the same process done on an industrial scale. Especially if it's the sort of complicated mechanical process that requires maintenance and safety considerations.
The big question is "how can we build a H2 electrolyser whose fixed cost isn't prohibitively expensive". Everything else will fall out from there. That will mean finding something else to use for the electrodes other than platinum.
Hydrogen burns invisibly to the human eye [1]. It must be approached with caution lest one get burned. I have heard of a case where leaks detection consists of wiping pipes with a straw broom and noting if it bursts into flame.
Perhaps such a setup could come with a system to inject a small amount of additives from a replaceable canister to give the flame color, and to give the gas an odor in case of leaks like they do with natural gas. I'm not chemist so I don't know if that's a possibility with hydrogen.
That's interesting, I never considered cooking with hydrogen gas. I think I assumed the steam production and very rapid burn would make it unsuitable, but this article from, er, the American Hydrogen Association says otherwise: https://www.clean-air.org/faq.html
Combustion of methane also produces steam, so that would not necessarily make a big difference. Hydrogen also does not necessarily burn any faster than other gases used for cooking, you just need to adjust the cooking apparatus for a different rate of gas flow.
This comment just helped me to answer the question of why there's instantly condensation on the outside of the pot when the gas stove is lit. That one had me curious for a while. Brilliant, thanks!
This company is building such a system, to shift home rooftop solar power into the winter. (To shift from day to night, batteries are more efficient.) https://www.homepowersolutions.de/en/product/
Why bother when you can just sell the electricity to the grid? What advantage does all that extra complication get you? Much cheaper to just scrap the gas hob and buy an induction hob and replace some of the pans.
This is for when you can't "just sell the electricity to the grid", either because it is congested or because you have more electricity at the moment than there is consumer demand available. An example off the top of my mind is in the North of the Netherlands, where the power cables from several major wind parks will come ashore. During periods of high production and limited demand, like a storm during the weekend, there will be more production than they can shift with the infra available. Shell is building a multi-GW electrolyzer plant to absorb the excess energy.
There are also some industrial applications like steel smelting where some chemical reducing agent is required, which would be difficult to convert to electricity-only operation. Fertilizer production is also pretty hydrogen-heavy.
The two big problems I see are that hydrogen is trickier to pipe than natural gas, and if there is no hydrogen economy to make backup deliveries, how do you keep up with essential heating when there isn't much excess electricity?