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.
Do you mean 3kwh/day of energy, or an output that has a daily peak of 3kw? Or something else?
Because kw/day isn't a sensible unit for either total energy or output.
How do you produce 3kw/day? How many solar panels do you have? Where do you live?
Create a big freezer room to store big amounts of meat or other foods for other people
Keep servers runing, offer a mini cloud or webhosting using that electricity
To charge electric cars in your neighborhood maybe is a good idea?
Make a cryptocurrency of course.