That's where I was looking, on ebay. The batteries that I was looking at are these 2 X 12v NEW 110AH LOW HEIGHT LEISURE BATTERIES NEW | eBay, the panels are these ones 200W solar panels-2x100W 12V Photovoltaic PV Solar Panel Module 12V RV Boat | eBay and the charge controller is this one Biard 20 Amp Solar PV Panel Charge Controller - Protects Battery - LED Indicator | eBay

Not so sure I'll grid tie them but might look at an inverter to run some bits in the shed as I'm in rented accommodation now and don't want to pay for altering the electrics. If I do look at getting an inverter then I might get more batteries and solar panels as I'm only going to be in the shed for a couple of hours every evening (well only if SWMBO allows!) and on the weekends.

Certainly something to look into!