Performance study and analysis of an inclined concentrated photovoltaic-phase change material system

The performance of an inclined concentrated photovoltaic-phase change material (CPV-PCM) system is investigated. The influence of a CPV-PCM system inclination angle in the range of -45 degrees to 90 degrees in an interval of 45 degrees, with a concentration ratio (CR) of 5, and 20, and a phase change material thickness of 50, and 200 mm, is considered. To determine the effect of these variables on the thermal and electrical behavior of the system, a comprehensive model comprising of the energy equations for CPV layers and a transient melting-solidification thermo-fluid model for the phase change material is developed. The model is numerically simulated, and the predicted results are validated using the available experimental and numerical data. Results indicate that the CPV-PCM system inclination angle has a notable effect on the time required to reach the complete melting state, the transient variation of average cell temperature, and PV local temperature uniformity. It is found that a remarkable reduction of the average solar cell temperature with enhanced uniformity is achieved, as the inclination angle varies from 0 degrees to 90 degrees. On the contrary, at an inclination angle of -45 degrees, the maximum average temperature along with an unfavorable abrupt change of local cell temperature is obtained. In addition, at an inclination angle of 45 degrees, the highest cell electrical efficiency is attained for the entire time period until complete melting occurs, whereas at an inclination angle of -45 degrees, the solar cell electrical efficiency is dramatically reduced with time. The findings of the present study reveal that the CPV-PCM at an inclination angle of 45 degrees reaches the minimum average temperature with reasonable uniformity of local solar cell temperature. These conditions achieve the highest solar cell electrical efficiency and help to prevent hot spots in the solar cell. (C) 2017 Elsevier Ltd. All rights reserved.