We had solar lights fitted to our yard this winter. We went carefully into how much time we would need lights for. Possibly all night in the case of a sick or injured horse and purchased the panel, the box of gizmo, and a huge battery to suit. Now that we really don't use lights, it being summer time we also wired it all up to our electric fence and it trickle charges it all the time. It seems very efficient. Our panel doesn't necessarily need sunshine, just light. Speak to these folk :- Cleversolar.co.uk. We bought our set up from them and they were very helpful.
Thanks both of you. I only strip graze him from April to generally September. So was thinking there would be hopefully enough sun / light and it wouldn't be too cold. Winter months I wouldn't use it at all.
My neighbour has rigged one up with bits he bought off ebay. I don't think it has been hugely tested yet because the 12V/ 850Ah battery he is using with it was fully charged when he set it up and the fence doesn't really take a lot off it. But he has poked about with a testing meter and is happy that it charges enough on bright days to keep it going. Well worth a look, but I would check it now and then to make sure the battery is still charged