Can I use a photovoltaic (PV) solar panel to power the pump and controller?
This is not something we recommend. If run off the mains, the pump uses 30-40 watts when on and is likely to be running for 1000-2000 hours per year. The controller is on all the time but uses only a trivial amount of power. So replacing this power use by PV is effectively like buying a PV cell to power half a light-bulb elsewhere in the house. It can be done but the batteries and inverter needed to make permanent, 240-volt AC current from a PV cell are expensive and batteries don’t last forever. Some systems use a 12-volt pump and simply provide it with power when the sun is shining, so removing the need for the inverter and battery. Again this is possible but in our view has two snags: we do not believe 12-volt pumps are as reliable as the tried and tested 240 volt ones. Secondly, one sacrifices all the information provided by the controller. There may also be times on dull days when the light is bright enough to provide heat in the panel but not enough to drive the pump. So, while a
