Experimental and theoretical calculation of efficiency for flat plate solar collectors in Erbil city

Solar plate collectors are utilized to heat up water or a mixture of water and glycol by capturing solar radiation and transfer this heat to the collector fluid. In this study, the efficiency of solar plate collector during 19th, 20th and 21st of February, was investigated experimentally. The time of day, plate collector mean temperature, solar intensity and external air temperature can effect on the efficiency of solar collector. And the effect of incidence angle on solar irradiation has been studied; as a result, the solar irradiance will be decreased as the angle of incidence increased. A method presented can be used to calculate hour angle, diffuse solar radiation and total solar radiation at various temperatures in this paper its MATLAB programs.