Performance investigation of truncated low concentrating photovoltaic-thermal systems with V-trough, compound hyperbolic and compound parabolic concentrators

Abstract

The electric conversion efficiency of a conventional photovoltaic cell in the market is around 13-22%. The remaining part is converted into heat. It increases the temperature of the photovoltaic cell and decreases the electrical efficiency. In concentrating photovoltaic systems, it comes into prominence. In this study, a comparative performance analysis was carried out among non-imaging concentrating photovoltaic thermal systems with various truncation levels of the reflector to attain uniform illumination and better electrical and thermal energy conversion performance. Compound Parabolic, V-trough, and Compound Hyperbolic concentrators were evaluated in terms of optical performance to decide distinctive truncation levels. The reflector sizes of 72%, 55%, and 42% were considered for evaluating the concentrating photovoltaic-thermal systems. The results show that the truncation reduces the photovoltaic cell temperature and provides more uniform temperature distribution. In the case of Compound Parabolic Concentrator- photovoltaic thermal, the average thermal and electrical power generation decreases by only 0.5% and 1.3% for 28% truncation. Compound parabolic hyperbolic- photovoltaic thermal provided about 45.5% and 21.7% higher average thermal energy generation per unit reflector area compared to V-trough and CPC, respectively. CHC provided about 59.8% and 32.8% higher average electrical power generation per unit reflector area compared to V-trough and CPC, respectively. Truncation reduces the thermal and electrical power generation while the power generation per unit reflector area increases. It indicates that the truncation provides effective use of the reflector. Compound Hyperbolic Photovoltaic Thermal system has the highest power generation per unit reflector area for all truncation levels and incidence angles.