Solar

I'm not either of you guys, but there do unironically exist people who find employment more depressing than alternatives. None of the standard motivators in society to get an employment work on them which really is a shame because they often are quite skilled.

The main current problem with solar is that it costs too much, it's not a large enough part of the grid that storage is an issue

It's cheaper to have natural gas plants that turn on when demand exceeds supply instead of storing energy

If you are storing energy in some way other than batteries, it's much more efficient to pump water up to a reservoir or compress air

Solar power systems actually pays off after just 10-15 years, and that's as far north as Europe. On peak mid day sunny days it can produce some 50% of electricity in Germany and on average as much as 6% of the total electricity. If you gave those numbers to people back in the 80s or early 90s it would probably have been disregarded as unrealistic crazy hippie fantasies.

Yes you can regulate by steering the amount of fuel non-solar plants use. For example have water power plant save up some water in reservoirs day time and use it during night. Or have a fuel based plant slow down to save fuel during day time et.c.

Because it takes more energy to break a water molecule than the energy that would be produced by burning the hydrogen.

Yes no storage process is 100% efficient. That is why steps 1-3 of answer could sometimes be more efficient than bothering with storage if it could be avoided.

I have a conjecture that gravity does not act as a force, only as an acceleration due to warping space time. You can only feel the force from trying to resist the acceleration of gravity.