solar panels, windturbines, energy efficient boilers and cavity wall insulation

A_fiend_for_life

greenbee wrote: »

For those of you who want to maximise the efficiency of your solar panels (both photovoltaic & solar thermal) they work best when combined with a green roof. The efficiency of solar panels is reduced as the temperature increases, and the vegetation helps to keep them cool.

You would think then you would get panels that have a cooling water jacket or layer, perhaps behind them, and in contact with the panel. That way a thin layer of water is heated and the solar panel has a higher efficiency. Or do water cooled solar panels already exist at a silly price?