Thermal Management of Solar Photovoltaics Modules for Enhanced Power Generation

Abstract

AbstractIndustry and government interest in solar energy has increased in recent years in the Middle East. However, despite high levels of solar irradiance in the Arabian Gulf harsh climatic conditions adversely affect the electrical performance of solar photovoltaics (PV). The objective of this study is to compare the annual performance characteristics of solar PV modules that utilize either sun-tracking or water cooling to increase electrical power generation relative to that of stationary, passively cooled modules in the Middle East climatic conditions. This is achieved using an electro-thermal model developed and validated against experimental data acquired in this study. The model is used to predict the annual electrical power output of a 140 W PV module in Abu Dhabi (24.43 °N, 54.45 °E) under four operating conditions: (i) stationary geographical south facing orientation with passive air cooling, (ii) sun-tracked orientation with passive air cooling, (iii) stationary geographical south facing orientation with water cooling at ambient air temperature, and (iv) stationary geographical south facing orientation with water refrigerated at either 10 or 20 °C below ambient air temperature. For air cooled modules, sun-tracking is found to enhance annual electrical power output by 15 % relative to stationary conditions. For water cooled modules, annual electrical power output increases by 22 % for water at ambient air temperature, and by 28 and 31 % for water refrigerated at 10 and 20 °C below ambient air temperature, respectively. 80 % of the annual output enhancement obtained using water cooling occurs between the months of May and October. Finally, whereas the annual yield enhancement obtained with water cooling at ambient air temperature from May to October is of 18 % relative to stationary passive cooling conditions, sun-tracking over the complete year produces an enhancement of only 15 % relative to stationary passive cooling conditions.KeywordsSolar energyCoolingRefrigeration