My cynical side was quick to point out that I would fire up my crypto miners if electricity was free for a few hours a day. After talking to him more I realized we both had different take aways from the story of "the tragedy of the commons" I lightened the conversation up by informing him he could do folding from home for a few hours to make sure his excess power went to a noble cause & thwart my zero sum approach.
I dunno, if electricity was free only for a few hours, I would use it to charge batteries, and then use that stored electricity later in the day when it's not free.
If electricity was free most or all of the time, and/or if I could store more than I could use, then sure, I'd probably use it for unnecessary things that some might consider wasteful (not crypto mining; I'm allergic).
I doubt the economics work, but I'd love to live in a world where a lot of the grid's battery storage is based on backup batteries people have at their houses with the added bonus of reducing their billing costs.