Organic Phase Change Cooled Photovoltaic Panels

Photo-voltaic panels lose efficiency as the temperature of the panel increases. A typical panel’s output can drop 40% or more on hot, high solar irradiation days when the highest potential for generation exists. Solar panels are typically uncooled, although CoolPV from Fafco mates a HDPE tubing mat to the rear of a panel, allowing cooling water to both improve the electrical efficiency and create hot water for residential use. Taking this concept one step further, phase change cooling was investigated with an organic liquid (R-245a) introduced in the tubing behind a CoolPV panel either at atmospheric pressure or set with a pressure relief valve at 20 PSI, and allowed to boil to cool the panel. The vapor was collected and condensed. Although this system was batch based, the final implementation would be a constant flow system similar to water cooled panels. The efficiency of standard panels, water cooled panels, and organic phase change panels are compared in this poster. The eventual aim is to couple an Organic Rankine Cycle (ORC) to an array of photo-voltaic cells, converting the removed heat energy into usable electrical power.