To be sure, they're a cost -- but at least in America, LiFePo4 batteries are practically being given away right now -- 100Ah@12V for ~$100 US. I suspect these are the "let's make hay before the tariffs hit" prices, but there are a lot of unpronounceable brands making surprisingly high quality products in the space.
As for off-peak storage, these would allow you to replace a Tesla powerwall for ~$600-750 US. I don't know your country, or its peaks (or valleys) but on my sailboat, off-peak is night time or cloudy days, and in sunny climes, 600ah gets me nigh infinite power. Without clear skies, I'm limited to ~4-5 days of normal consumption.
(Not trying to nudge you off your position at all, just sort of reflecting/remarking at how practicable this all is at the moment.)
As for off-peak storage, these would allow you to replace a Tesla powerwall for ~$600-750 US. I don't know your country, or its peaks (or valleys) but on my sailboat, off-peak is night time or cloudy days, and in sunny climes, 600ah gets me nigh infinite power. Without clear skies, I'm limited to ~4-5 days of normal consumption.
(Not trying to nudge you off your position at all, just sort of reflecting/remarking at how practicable this all is at the moment.)