I read a very interesting article in the Guardian recently (no, I am not a habitual Grauniad reader!) about solar power in Australia. Apparently the trend in some areas is to go off grid and as self-sufficient as possible, due in first case because of the high cost of electricity. Anyway, the article gave several sources for supply of equipment. The main site for battery storage ws given as
http://onestepoffthegrid.com.au/.
Yes, it is an Australian site, but the equipment is generally available worldwide. It makes interesting reading.
The only thing necessary for the triumph of evil is for good men to do nothing.