Effects of Dynamic Shading on Thermal Exergy and Exergy Efficiency of a Photovoltaic Array

Abstract

In this study, the effects of dynamic shading caused by an incorrectly positioned transformer building in a Photovoltaic array were investigated regarding the exergy efficiency and thermal exergy for a year. Experimental and theoretical results show that the thermal exergy is affected by the surface temperature of solar panels depending on their shading ratio. In addition, as the shading ratio increases, the electrical exergy and power conversion efficiency decrease. It is also seen that the thermal exergy and exergy efficiency of the PV power system is negatively affected by the increasing solar cell temperature. The average shading ratio of 3.11% during a year causes an increase of about 23.32% of the thermal exergy, and loss in power conversion efficiency of about 4.88% and loss in exergy efficiency of about 13.72% over a year. Overall, it can be concluded that the long-term shading will significantly adversely affect the PV array performance in terms of electrical exergy and thermal exergy.

Keywords

• dynamic shading
• electrical exerg
• exergy efficiency
• photovoltaic array
• thermal exergy