Improving photovoltaic (PV) panel performance under extreme climatic conditions is critical for advancing sustainable energy systems. In hyper-arid regions, elevated operating temperatures significantly reduce panel efficiency and lifespan. To guard against heat-related performance degradation, researchers are evaluating the utility of stagnant water layer cooling technology for solar panels.

An experimental setup tested the cooling technology in eastern India using seawater, tap water and desalinated water. Researchers from the Indian Institute of Petroleum and Energy (India), Andhra University (India), Rajiv Gandhi Institute of Petroleum Technology (India) and University of Jaen (Spain) compared the performance of an uncooled PV module with that of the water-immersion cooled 10 W PV module in terms of energy output, electrical efficiency, exergy efficiency and sustainability index.

The modules were covered with a 1.0 cm-thick stagnant layer of each water type. For the cooled panel, four transparent glass strips, each 3.0 mm thick and 30.0 mm high, were attached along the perimeter of the front surface of the PV module using silicone adhesive.

The study published in Scientific Reports documents that the desalinated water produced the greatest temperature reduction of 8.2° C compared to the reference module, resulting in a 28.3% increase in daily energy output. Seawater reduced the module temperature by 7.4° C and boosted output by 14.9%, while tap water achieved a 7.2° C temperature decrease and a 16.6% increase in energy output.

The seawater-based PV array achieved the lowest electricity generation cost and outperformed both tap-water and desalinated-water-based arrays in terms of module lifespan. The desalinated-water-based system demonstrated the best environmental performance in terms of carbon dioxide emissions reduction over a 20-year lifetime.