It’s still not earning you money to spend electricity because you still have to pay the transfer fee which is around 6 cents / kWh but it’s pretty damn cheap nevertheless, mostly because of the excess in wind energy.
Last winter because of a mistake it dropped down to negative 50 cents / kWh for few hours, averaging negative 20 cents for the entire day. People were literally earning money by spending electricity. Some were running electric heaters outside in the middle of the winter.
Splitting water and keeping the H2 converts the energy into chemical energy. The oxygen is just dumped into the atmosphere, which is a loss of efficiency I think? What I know, H2 is the highest form of chemical energy there is.
Some processes require burning, or cannot be electrified otherwise. It’s these where the hydrogen is needed directly. I think hydrogen is a source material that should be mostly be converted into other chemicals. Etc. methanol and ammonia are more easily storable, unlike diatomic hydrogen which can slowly diffuse through a metal wall, enbrittleling it. Clean ammonia production could replace a giant mass of fossil fuels.
Here is an another rabbit hole: most of your body’s nitrogen is from ammonia and the fertilizers made from it.