The goal of this project is to improve the efficiency of the solar cells. Temperature in excess may cause degradation of photovoltaic (PV) panels. An aluminium sheet of 0.8mm thickness and a rubber tube are placed underneath the 4W solar panel. A water pump is employed to circulate water from pail through the rubber tube to ensure water flows continuously behind the PV panel throughout the day. The water coolant system may help the solar panel to cool down and increase energy output by 1.4% during clear and sunny days.