A Practical Approach for Estimating the Optimum Tilt Angle of a Photovoltaic Panel for a Long Period—Experimental Recorded Data

In this study, recorded empirical data were applied with a practical approach to investigate the optimal tilt angle of flat plate collectors facing south for long period in Tehran, Iran. The included 20 years average total radiation on horizontal plane Tehran’s meteorological station. Based previous studies, annual optimum Tehran was estimated at 33 degrees annually; however, estimation does not focus energy absorption and effectiveness changing monthly, seasonally, bi-annually via measured data. This paper aims explain distinction between various receptions different adjustments. study shows that solar cumulative gained monthly can be approximately 7% higher than achieved an setup. Additionally, seasonal bi-annual angles have about 6% more Moreover, consideration similar received radiation, results illustrate set up 20% greater summer months adjustment.