With the cost of electric going up with everything else my BIL has bought PV panels to go on the roof of his shed but doesn't intended to connect them to the mains. He says no point with the lack of feed in tariff. Instead he will connect up to stand alone immersion heater setup in the hot water tank to heat water for heating his house and general hot water duties. It's making me think about getting some on the workshop roof to ease back the electricity cost a bit. All being well when you do the sums it does add up but what has everyone else found with these panels, are they worth it?