Efficiency improvement of photovoltaic panels by using biaxial solar tracker and automatic washing arm

Since the removal of dust and sand accumulated on photovoltaic panels and placing the surface of these panels perpendicular to the sun's rays increase the absorption of the panel to a significant extent, in this article the results of design an automatic mechanism consisting of an arm with two degrees of freedom to track the sun and another automatic mechanism to wash the panel with a brush is presented. This system is designed to clean the photovoltaic panel from pollution with a moving washing brush on the sliding rail and the sprinkler pump system. Moreover, the sun is followed in the direction of azimuth and altitude by using two motors in the mechanism to place the panel perpendicular to the sun's rays. Several tests were carried out to find the best period length of programming the automatic wash to achieve maximum attainable electrical energy from the panel considering the consumption of tracker and washing subsystems. After conducting numerous tests with different period lengths, the best period result was 14 days, which can improve the panel power by about 10% compared by the case of not using the washing subsystem.