Is solarPV a waste?
My understanding is that:
1/ Solar thermal has a longer generating opportunity than solar PV, because it can exploit radiation that passes through clouds, which PV cannot match.
2/ The larger a Stirling engine is the more efficient it is (and I believe a large thermal gradient helps too)
So I don't understand why Solar farms use PV when they could use solar thermal to create a significant thermal gradient to a large (and pretty efficient) Stirling engine, to turn its kinetic energy into electricity directly or for example, store the heat in an aquifer to help drive the Stirling engine at other times.
I realise energy conversion losses will be in play here but I understand PV isn't very efficient, particularly in a cloudy country like the UK?