On Fri, 19 Jul 2013 21:35:45 +0100, Colin Stamp
wrote:

There may still be some mileage in using batteries though. This bloke
claims to have made an inverter and a set of traction batteries pay for
itself by charging on economy 7 overnight and running background loads
during the day. He keeps the big loads away from it, of course, and I
think he knows where to get the kit cheap.

You'd have to get it cheap - in the early days I knew of telecoms,
fork truck and even submarine batteries being used, but they were all
bought for scrap prices and salvaged good ones made up of parts.
Otherwise, budget for a new battery bank every five years or so and if
you pay normal prices for that, forget it.