>>1755175solar power is very cheap, battery storage very expensive (but both always getting cheaper, solar very very quickly per watt at least, and batteries pretty slowly but surely). use LFP chemistry, its relatively safe (much much much safer than most lithium based, but not nearly as safe as LTO, so i only call it relatively safe, many would disagree with this way of phrasing it tho obviously). if u can afford LTO get LTO though, but youre going to be paying double/triple what you would have for LFP but they will also last much longer supposedly (untested since theyre less than 30 years recently developed but if what engineers currently understand about battery aging and dendrite formation and whatever then the shelf lives they advertize are worth trusting)