Affiliation:
1. AL-Turath collage university
Abstract
Because of the shadow of high buildings and huge urban development that the world is witnessing, especially in the large cities such as Istanbul, this led to prevent taking advantage from a large part of the falling solar radiation, which led to finding alternative solutions for the purpose of benefiting from the falling solar radiation. Among these solutions is the adjusting solar panel at the optimum slope and orientation angle. So the purpose of this study is to determine the optimum slope and orientation angle for a photovoltaic panel in Istanbul (Turkey) with coordinate of (41° 1′ 0″ N, 28° 58′ 0″ E), latitude of (Ø = 41.0167), and explain the effect of azimuth angle on the optimum slope angle of solar radiation on the photovoltaic panel. A mathematical model was developed by Klein and Theilacker to determine any surface azimuth angle (ϒ) was used to estimate the total solar radiation on the slope photovoltaic panel surface, also Liu – Jordan model was used for calculating the optimum tilt angle for south face direction and then comparison results with two models. In our study we used a Microsoft Excel spreadsheet to determine optimum slope (β) and azimuth (orientation) (ϒ) surface angles for any city only by changing the coordinate and horizontal solar radiation of the selected city. For calculation purposes, horizontal solar radiation data for the city of Istanbul was obtained from the prediction of worldwide energy resources (power) by NASA. The optimum tilt (β) and azimuth (ϒ) angles were determined by searching for the values of angles for which the total radiation on the PV surface was maximum throughout the year. And for the specific azimuth angle (ϒ) changes from (0 to 90) degree It is found that the optimum tilt angle (β) should be changed to observe the maximum solar radiation. The annual maximum solar radiation in Istanbul city for azimuth angle greater than 0o was 6033 Mj/m2 at azimuth angle equal to 10o and tilt angle equal to 30o.