Performance and water-energy nexus aspects of stagnant water layer cooled zero-tilt solar photovoltaic module

Abstract

This study proposes a novel stagnant water layer cooling concept to enhance performance of solar photovoltaic (PV) modules. Three distinct types of water—seawater (Scenario 1), tap water (Scenario 2), and desalinated water (Scenario 3)—were utilized to cool a 10 WP polycrystalline PV module by establishing a stagnant layer of 1.0 cm thickness over it, under the climatic conditions of Visakhapatnam (17.62°N, 83.21°E), India. The average daily temperature variations between the reference and modified PV modules were approximately 7.0 °C, 7.2 °C, and 8.2 °C for Scenarios 1, 2, and 3, respectively. The daily average electrical efficiency & energy output of the modified PV modules under Scenarios 1, 2, and 3 were approximately 16.2 & 14.9, 18.6 & 16.6, and 30.8 & 28.3%, relatively higher than the reference PV module, respectively. Exergy efficiency, sustainability index and specific CO2 emission of desalinated water-cooled PV module were 7.41%, 1.08, and 406 g/kWh, respectively. However, the desalinated water-cooled PV module exhibited 29.1 and 15.1% higher evaporation losses than those of the seawater and tap water-cooled PV modules, respectively, under similar solar energy of 21.4 MJ/m²d. The proposed cooling technique is effective and economic, depends on the type of utilized water.