So where is the most efficient place for solar panels, given that the solar panels are heated by the sun, they could be coated to reflected IR. A cooler climate

So where is the most efficient place for solar panels, given that the solar panels are heated by the sun, they could be coated to reflected IR. A cooler climate could help heat be convected away. High altitude deserts like the Atacama might be ideal, but there's less atmosphere for convective heat transfer. I do love an optimisation challenge.