Hydrogen fuel cells begin to show off in the world of competitive racing

[longship]

17. I like it to even out the day/night solar power cycle

Use excess solar to split water and store the H2. Save the O2 also, of you wish. When the sun goes down, use the H2 to generate clean energy until the sun roses the next AM.

Repeat as needed.

Also usable for wind or tidal.

Plus, if you have extra H2 you can use it to fuel autos, airplanes, trains, almost anything with zero carbon emission.

Unfortunately, the only way to get H2 is by way of some other power source. A hydrogen economy depends on other clean sources.