Integrated Internal Heat Sinks for passive cooling of photovoltaic modules

Abstract

High operating temperatures harm photovoltaic (PV) modules. The increase in temperature of the cells leads to lower open circuit voltage and higher short circuit current ultimately leading to a lower power output due to a negative thermal coefficient. Hence, lowering the temperature of commercial crystalline silicon modules during their operation becomes desirable, as it increases the system's energy yield and prolongs the module's lifespan. Throughout the years several attempts have been made to decrease the temperature of PV modules, characterized my two main groups of cooling techniques, active and passive cooling techniques. Active cooling techniques require additional power to cool the panels whereas passive cooling techniques rely on natural convection and require no additional power input. In this thesis, we experimentally investigate the cooling potential of a novel passive cooling method that integrates an internal heat sink into PV modules. The basic idea of the technology is to create a thermal circuit beneath the solar cell that allows for the extraction of the heat directly from the solar cell to the outside environment. The experiments started on a single solar cell, to find the best configuration. We adapted the optimized design onto a 2x2 PV and a 3x3 PV module. Finally, the internal heat sinks were connected to a frame. We observed a temperature reduction of around 4-5°C on the module with the internal heat sink compared to a Standard module under the same environmental conditions.