Research Paper Correlation between the Power Output and Exposure to Sunlight of a Solar Panel

Familusi, T.O... [et.all];

The degree of dependence of power delivered by a solar panel on
input solar irradiance was examined with a 10watt polycrystalline silicon (Si) solar panel and a 10watt polycrystalline gallium Arsenide (GaAs) solar panel, each at a fill-factor of 0.7.The research was carried out at Ilesa city located at coordinates 7037′0″N 4043′00E / 7.616670N4.716670E, in Osun State of
Nigeria. The research experiment was carried out from December 10th to 23rd, 2013 and March 10thto 23rd, 2014. Average solar isolation figure for Ilesa measured in kWh/m2/day onto a solar panel where the angle is adjusted each month to get optimum sunlight is 4.44 in March and 5.0 in December.The solar
panels were hindered by different quantities of dust particles from receiving the appropriate sunlight. The particles used are sieved fine mud dust used in the following concentrations: 0.0ml, 2.5ml, 5.0ml, 7.5ml, 10.0ml, 12.5ml and 15ml respectively to shield the surface of the panels from normal exposure to
the rays of sunlight. Measurements were taken of short circuit current (Isc) and open circuit voltage (Voc) values at intervals 1hour from 10.00am and 5.00pm.The output power and percentage power loss were calculated. The results show that the effect of any shielding the surface of a solar panel from
receiving sunlight in appropriate abundance is vital. At 0.0ml dust particles on the surface of the solar panels, that is, when the surfaces are free from dust particles, the power loss is 0.00%. The percentage power loss rose from 0.00% to as high as 71.69% in polycrystalline silicon solar panel and 75.35% in
polycrystalline GaAs solar panel during December, 2013 as the shielding dust particles volume rose up to15.0ml. Also, in March, 2014 the percentage power loss rose from 0.00% to as high as 71.94% with polycrystalline silicon solar panel and 75.60% with polycrystalline GaAs solar panel. These high values of power loss in both panels and periods of experimental investigation, suggest
that the surface of solar panels should be kept free of dust particles or any other materials that can cause a shield or prevent the solar panels from receiving optimum sunlight at a time.