This is a cooler that uses a simple micro irrigation (sprinkler) system to cool the solar PV panels on my roof. It uses a Picaxe microcontroller and temperature sensors to control the cooling so only the minimum amount of cooling is used. The microcontroller is configured to start the cooling cycle whenever the panels reach 8 degrees above ambient. This increases power output by around 20%. The cooling is based on evaporation- almost no water drips off the panels.