A　novel　micro　heat　pipe　array　was　used　in　solar　panel　cooling.　Both　of　air-cooling　and　water-cooling　conditions　under　nature　convection　condition　were　investigated　in　this　paper.　Compared　with　the　ordinary　solar　panel,　the　maximum　difference　of　the　photoelectric　conversion　efficiency　is　2.6%,　the　temperature　reduces　maximally　by　4.7　°C,　the　output　power　increases　maximally　by　8.4%　for　the　solar　panel　with　heat　pipe　using　air-cooling,　when　the　daily　radiation　value　is　26.3　MJ.　Compared　with　the　solar　panel　with　heat　pipe　using　air-cooling,　the　maximum　difference　of　the　photoelectric　conversion　efficiency　is　3%,　the　temperature　reduces　maximally　by　8　°C,　the　output　power　increases　maximally　by　13.9%　for　the　solar　panel　with　heat　pipe　using　water-cooling,　when　the　daily　radiation　value　is　21.9　MJ.　©2010　IEEE.