Efficiency of solar PV cells is linearly dependent on its temperature. Per each degree Celsius above standard test conditions (STC, traditionally 25ºC), efficiency of traditional solar PV cells decreases by 0.5%. Depending on the installation site, operational temperature can be more than 50ºC above standard temperature, with a corresponding reduction in efficiency of more than 25%. Therefore, there is a strong interest not only to develop new solar PV cells made of materials with lower thermal sensitivity (i.e. minimization of the thermal sensitivity), but also to find strategies that can help mitigate the thermal losses. In this research project, we aimed to enhance convective cooling of solar PV systems through the design of innovative solar module arrangement strategies. The objective is to find new approaches to the installation of solar modules that can boost energy harvesting efficiency through the reduction of thermal losses by simple and costless changes of arrangement. For this purpose, we have developed an array of field experiments, scaled wind tunnel measurements, and controlled numerical simulations. Results show once again that sometimes the simpler approaches, which can easily be neglected, can also be the most favorable ones. This work illustrates the relevant role that fluid mechanics plays in the critical goal of developing new and more efficient renewable energy systems.
Marc Calaf is an Associate Professor in the Mechanical Engineering Department at University of Utah, and head of the Wind Energy and Turbulence Laboratory. Originally from Barcelona, with a degree in Physics, and a Ph.D. in Mechanical Engineering from the Swiss Federal Institute of Technology Lausanne (Switzerland), his research interest range from fundamental fluid mechanics and turbulence, renewable energy systems, and the atmospheric boundary layer. His expertise encompasses both, numerical simulations and field measurements. He has served as an Associate Editor in the Journal of Renewable and Sustainable Energies over the past few years, and currently serves as an AE in the Journal of Atmospheric Sciences.