Well, until '27, I'm allowed to use the grid as a free battery, basically, this is a kind of government subsidy. But that will end, and the contracts available will be fixed price with a feed in tariff or dynamic (realtime) market price, but then prices can and have been negative during peak solar hours. A battery can solve this only for a bit, and maybe with smart algorithms it can be trading on the electricity market full time, I'm not sure if that makes enough money for the grid power in winter.. it's nice to think about though.