Ask HN: What should I do with ~3kw/day surplus solar electricity?

I am currently only using about a third of the electricity my home solar+battery system produces. The surplus is going to the grid where I am accumulating credits from my utility. Could I be using this electricity for something else, better than sending it to the grid? Or, maybe there are fun/interesting ways I could be using it? For some reason purifying water or producing hydrogen comes to mind, but not sure that makes any sense.