Reducing the operating temperature and improving the efficiency of PV modules using guiding vanes

Reduction of the operating temperature of photovoltaic cells can significantly increase their efficiency. An effective way of reducing this temperature is to redirect ambient air to carry some of the thermal energy away from the modules. In this work, guiding vanes placed under the modules are used to accomplish that. The shapes, sizes, and locations of the proposed vanes are optimized to give the greatest temperature reduction based on realistic conditions found in the Kabd Desert of Kuwait. A 2D finite element model, validated using an experimental PV module built in the Kabd desert of Kuwait. Optimum vanes were found for multiple rows of modules, resulting in temperature reductions of 8–12.6 °C for the representative late-spring day tested. With such decreases in operating temperature, a typical solar module operating in such conditions can increase in efficiency roughly from 17% to 18%. Specific airflow patterns around the optimized vanes/modules were found to be a key factor. The vanes gradually divert increasing fractions of wind towards the backs of the modules. The fractions of air flowing above the vanes, onto the back of the module, compared to those going below the vane, continuing on the next module, go from 28%–72% to 43%–57% to 64%–36% to finally 73%–27%. The vanes optimally apportion the cooling potential, thereby lowering the maximum temperature across the entire array. The results demonstrate and quantify the efficacy of such guiding vanes in lowering the temperature and increasing the efficiency of PV modules. It also extends the area of passive cooling of PV modules and points towards possible future directions.