that's actually better than I thought.

I think the problem is really with the excess. It is either rare and not enough to mine, or you have overpaid on the fv system, so your energy is actually expensive.

I can imagine two situations where it makes sense:

- you are traveling and not using the energy, nobody's at home

- you get access to spot prices and have batteries. when the energy is cheap or negative, you both mine and charge batteries (you can do this with Victron systems for example)