A Cooler Solar Panel: The Effect of Passive Cooling on the Efficiency of Photovoltaic Panels

Solar energy is becoming increasingly popular due to the vast number of locations in which they can be installed and the decreasing cost. The downside to solar energy comes from relatively low conversion efficiency of around 15-20%. If this efficiency increases the PV array will produce more power and PV systems will have a shorter payback period. One reason PV panels are inefficient comes from overheating. As the PV panel's temperature increases, the efficiency decreases at a rate of about 0.4-0.5% per degree Celsius. If the heat generated in the PV panels and the overall temperature can be reduced the panels will produce more energy and be more cost-effective. This study examined three techniques for cooling applying: 1) heat sinks 2) heat pipes and 3) vapor chambers. The heat sink increases surface area for passive convective heat transfer and the heat pipes and vapor chambers use latent heat to transfer heat away from the panel. Each of these three techniques was studied experimentally, comparing the temperature reduction potential. Each cooling method was studied experimentally in the indoor Energy Research Lab using a halogen lamp to mimic the sun's radiation. Each test recorded temperature data from the panels and electrical power output. In addition, a FLIR IR camera was used to acquire thermal images of the panels. This data allowed for the effects of cooling to be quantified.