Thermal Management of PV Panels using Passive Cooling Approaches

Abstract

Due to rising global warming and increased energy security around the world, there is an ever-increasing need for transition towards more cleaner and renewable energy sources around the world in place of conventional energy sources including fossil fuels such as coal, oil and Natural gas. Solar power among renewables is by far a promising solution in terms of cleaner and greener energy production and utilization, owing to its cheap cost, reliability and sustainability in the recent years. But there are still few challenges faced by researchers and engineers around the world in the field of solar power. Particularly, the inherent low efficiency due to absorption of only a portion of solar spectrum that can be converted into electricity. Furthermore, environmental factors such as temperature, humidity and dust also contribute towards the power degradation and thus, in turn, a low conversion efficiency. This project is aimed at utilizing the potential of various passive cooling approaches suggested by researchers to develop a working physical prototype of PV-PCM system which provides higher overall efficiency compared to the conventional PV Panel. Small scale 4 watts panels were obtained and phase change materials were utilized at the PV panel back to reduce their operating temperature and hence, to increase overall conversion efficiency. Phase change materials utilize their latent heat capacity to absorb large amounts of heat from panel back and change their phase from solid to liquid, resulting in reduced panel temperature due to increased heat transfer from panel back surface towards the ambient through PCM. Two different designs were tested for various electrical and thermal parameters: One with rectangular PCM containment and the other with tubular design. Both the systems showed significant reduction in panel temperature up to 5-6 degree Celsius. Container Design has an average relative efficiency increase of 1.55 % while tubes modification has an average efficiency improvement of 1.1 %. Similarly, 10 % improvement in terms of output power is observed for tubes modification and 15 % improvement in power output, at average, is observed compared to the conventional PV Panel.