Emulation for de-rating and degradation/turbidity factors effects on PV module

This work presents de-rating\degradation factors effect on photovoltaic (PV) module energy output. It studies the turbidity and the angular optical losses to facilitate a development of an index that evaluate the level of solar radiation degradation. It is performed in an algorithm that provides a solution of optical depth, solar incidence angle on tilted PV module, turbidity index, and angular losses. PV modeling and simulation is the tool in this research; de-rating and solar radiation degradation factors effects on PV module performance are implemented in MATLAB\M-File script, the results demonstrate the variation of loss and gain over the year out of the module rated output DC power corresponds to harsh ambient conditions including high turbidity index of 78.84%. The algorithm approach uses National Renewable Energy Lab/American Society of Testing and Measurements (NREL/ASTM) solar spectral irradiance of air mass 1.5 (AM1.5), Ångström turbidity coefficient, and National Aeronautics and Space Administration (NASA) surface metrology and solar energy over 22-years period.