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.
Sounds like a reasonable approach, at least if batteries keep improving and getting more cheaper as they did in the past. Working on things that work right now, like modern nuclear, seems like a reasonable addition.
When comparing cost of nuclear vs. wind or solar, it is very easy to get to smaller numbers. But then you have no storage and no massive infrastructure, which means solar and wind can not work. Omitting these costs is a nice way to make it more palatable, but not an honest approach when comparing different technologies.