EFFECT OF WATER COOLING ON PHOTOVOLTAIC PERFORMANCE

The efficiency of photovoltaic (PV) panels decreases as the panels' temperature increases. It is affected by various environmental parameters like temperature, dust, air velocity, and humidity.  Mainly temperature is the critical factor to obtain maximum efficiency.  One way of improving the efficiency of PV system is to maintain a low operating temperature by cooling it down during its operation period.  This paper experimentally presents a forced-water spraying and cooling technique with variable flow rate of water on PV modules surface to improve the panels efficiency and enhance the net power saving. The results showed an initial high performance ratio and indicated that, the decreasing rate in the panel surface temperature has a direct proportional relation with PV efficiency. It was observed that, operating the cooling system for one day results a decrease in solar cells temperature by 9.07 oC, and an increase in the solar cell output power by 1.73 Volt give an increasing in power gain and efficiency by 9.27%, 0.71% respectively.