L R AS Published on Sunday 6 September 2020 - n° 330 - Categories:R&D , panels
Compare the performance of a floor or floating installation
Moroccan researchers have compared the efficiency of panels placed on water with solar panels on land. They found that installations on water offer better energy efficiency than roof-mounted and ground-mounted photovoltaic systems. The operating temperatures of the panels are lower.
They used two chains of two identical 87.5 W panels. They were placed at an angle of inclination of 30° and oriented due south.
The tests were carried out over a period of five days, 9 hours a day with a measuring step of 10 minutes. Floating solar panels offer a better energy yield than photovoltaic systems mounted on roofs or on the ground, with lower panel operating temperatures. Scientists have measured the temperature of the back and front panels. Water cooling ensures a temperature difference of 2°C, with peaks of 5°C.
In terms of energy efficiency, the floating system has always outperformed the reference terrestrial system, with the floating technology achieving an average energy production gain of 2.33% per day compared to the terrestrial system.
The heat from the surface of the photovoltaic panels is transferred to the water basin, which acts as a cooling system.
The shading of the PV panels conserves water by reducing evaporation.
PV Magazine of 31 August
Editor's note This study only confirms what we know: panels on water are more productive than panels on land and reduce water evaporation. It quantified, which is useful. The study is done in Morocco. Would it achieve the same result in France?
Another point that is still unknown is whether the loss of electricity production on land-based panels is compensated for by the lower cost of land-based panels, or whether the gain in production from water-based installations is not cancelled out by the extra cost of the installation. This is still an unknown area of profitability.