Water Cooling Method to Improve the Performance of Field-Mounted, Insulated, and Concentrating Photovoltaic Modules

Abstract

The installation rate of crystalline silicon photovoltaic (PV) modules worldwide is at an all-time high and is projected to continue to grow as the cost of PV technology is reduced. It is important to note that PV power generation is heavily influenced by the local climate. In particular, for crystalline silicon-based PV devices, as the operating temperature of the panel increases, the efficiency decreases. Higher operating temperatures also lead to accelerated material and mechanical degradation, potentially compromising system effectiveness over the lifetime of the panels. In addition, atmospheric pollution can cause particle deposition on the surface of PV modules (soiling), reducing the amount of solar irradiance that reaches the PV material and reducing panel efficiency. Various cooling and cleaning methods have been proposed in the literature to mitigate these problems. In this study, a uniform film of water was continuously recirculated by pumping over the surface of a solar panel using an emitter head attached to the top of the panel. The water cooling technique was able to maintain panel temperature below 40 °C while adjacent untreated panels were operating near 55 °C. Besides the efficiency improvements due to cooling, the film of water also kept the panels clean, avoiding any reduced power output caused by panel soiling. Additional studies were carried out with artificially chilled cooling fluid, insulating materials, and side mirrors to examine the cooling system performance under different installation scenarios. Water cooling is concluded to be an effective means of increasing the efficiency of monocrystalline silicon photovoltaic panels. Under normal operating conditions, the increased energy output from the panels is more than sufficient to compensate for the energy required to pump the water.

The impact of height installation on the performance of PV panels integrated into a green roof in tropical conditions

“…There are some strategies to cool PV panels, such as irrigation [10], forced ventilation [4] and green roofs [1,7]. Scherba et al [1] indicate from simulations that green roofs reduce the surrounding temperature of roofs near to noon time in comparison with black roofs.…”

Experimental Analysis of Effect of Vegetation under PV Solar Panel on Performance of Polycrystalline Solar Panel

“…The efficiency is increased due to different type of vegetation and water tray, among of them water tray has highest efficiency. These results are analyzed by plotting the graphs between Radiation v/s Efficiency for each case, (Reading for analysis graphs are taken at no load on PV panel) [4][5][6].…”

“…The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. But solar cells perform better in cold rather than in hot climate and as things stand, panels are at 25˚C which can be significantly different from the real outdoor situation [4][5][6]. For each degree rise in temperature above 25˚C the panel output decays by about 0.25% for amorphous cells and about 0.4-0.5% for crystalline cells.…”

Design of a Hybrid Photovoltaic Thermal System in Lebanon

“…This continuous flow of water acts as a cooling method for the cells and a cleaning agent that reduces panel soiling [2].…”

“…The main desire of the researchers was to develop cells that have a low cost and a high efficiency [1]. The problem with photovoltaic panels is that their efficiency drops with temperature increase at a rate about 0.4-0.5% per 1℃ once the baseline temperature of 25℃ has been exceeded [2]. Several methods have been developed in order to limit the efficiency drop of PV panels by cooling them.…”