Experimental Study of the Effect of Submerged Cooling on the Performance of Photovoltaic Panels

Abstract

Day by day increase in demand for different forms of energy, especially electricity, is caused by increase in population and increase in the use of technologies in various aspects of human life. One way to overcome this problem is to increase the efficiency and power of photovoltaic systems and at the same time, to reduce the cost of electricity production. Solar radiation intensity and photovoltaic panel temperature, are the two effective parameters in the efficiency and power of photovoltaic panels. As the radiation intensity increases, so does the panel output and its temperature. If the panel’s tempetarue increases to high level, the panel may be damaged. Also, increase in panel’s temperature leads to reduction in its efficiency. Therefore, some kind of panel cooling is necessary, especially if concentrated radiation is to be used. One way of cooling the panels is to immerse them in a liquid. On the other hand, the coolant light transmittance characteristics, and its thermos-physical properties, affect the performance of the PV panel. In this research, properties of different liquid coolants are considered and methanol has been selected for further investigation. The effects of covering glass, air gap thickness, and the thickness of liquid coolant on the performance of the PV panel is investigated experimentally. Filling the gap between the glass cover and the panel leads to 6.6% increase in the panel’s efficiency whereas wen the glass cover is removed, the enhancement in efficiency for the submerged panel reaches 14.8%.