(Estimation of optimum tilt angle for solar panels, with the help of the incoming radiation (Case Study of Isfahan Province, Iran

Iran is a sunny country and In terms of amount of energy is one of the best countries. Electricity from Photovoltaic (PV) is by nature a fluctuating energy source due to the movement of the sun and varying cloud coverage causing variable availability throughout the day and seasons. The aim of this study is to provide a model for the initial assessment of the use of solar panels in Isfahan province and to estimate the optimal tilt angles for panels and we used data from NASA's Atmospheric Sciences Research Center of the amount of solar radiation that received from the surface of the panels in last 22 and whit regression and obtain a coefficients, test of the validity of errors was investigated. This study appropriately evaluates the radiation estimation models (linear model) whit SPSS software for initial assessment. Also some other models whit linear model was compared and the best one was introduced. According to the correlation coefficient for all angles except angles of 0, 45, 50 and 55, model was appropriate. As a result, summer is much warmer than winter, and the polar regions are dramatically colder than the tropics and the use of panels in cold seasons with the angle of 45 to 60 degree and in warm seasons whit the angle of less than 45 degree, especially less than 20 degrees to the horizon, will bring the highest payoff.

solar panels; optimal slope; Photovoltaic; Iran