One thing I have idly considered - what to do with the excess daily solar energy? Presumably the problem is only going to magnify over the coming years. Net-metering agreements are continuing to get worse, so it seems that the surplus electricity will go to waste.

Outside of bitcoin mining, is there any energy sink a residential user could engage to suck up the spare capacity? At the industrial scale - what processes can intermittently engage in production which is still cost effective if the equipment lays idle for a majority of the day?

Fuel synthesis? Desalination? SETI-like computations?