@UKMICKY just a thought on using batteries to store cheap electricity. you do realise you do not get back out what you put in! Each pass through the inverter loses about 8% and it will loose another 4% whilst inside the battery - so in total you will only get back out about 80% of what you put in
Therefor if you charge your batteries up during the night like i do at 7p per kwh, it is actually costing about 8.75p per kwh when the wastage is taken into account
and to be even more pedantic, each cycle reduces the life time of these batteries , lets say a 10kwh battery pack costing £2,500 lasts 7000 cycles, that works out at 36p per cycle. a 10kwh battery system is in reality only about 7.8kwh of usable power. so we can add another 4.6p per kwh
therefore cheap electricity bought and stored in a battery during the night a
t 7p, is really costing about 13p per kwh
it is still cheaper, a lot cheaper, it's half price leccy and we can't say that is not a good thing - but be very careful of the headline figures these solar companies bandy about