Modeling the Effect of PV Module Orientation on the Encapsulant Browning Degradation Rate in Algeria Region

The encapsulant browning degradation mode of photovoltaic (PV) modules is affected by ultraviolet irradiance, ambient temperature, and humidity of the installation site. In this article, the degradation rate for encapsulant browning, measured by short-circuit current degradation, is estimated for different PV module tilt and orientation angles in the Algiers region, characterized by a temperate climate. The activation energy for encapsulant browning is calculated using the acceleration factor modeling of the field-to-field degradation and physical models, in conjunction with the meteorological data of two locations in Algeria, where the same module type is fielded for 9-10 years. The tradeoff between the PV energy production and the PV module lifetime is carried out for different PV module positioning, assuming that encapsulant browning is the main failure mechanism experienced in the field. The results reveal that the orientation angle affects the PV module lifetime, where orienting the PV module from east to west increases the lifetime up to 30%, and the lifetime energy production up to 6%, due to reduced degradation. It is also presumed that although the Saharan region of Adrar receives more UV light and ambient temperatures throughout the year in Algeria, the PV modules fielded in the Mediterranean region of Algiers suffer higher degradation, which isexplained by the high humidity experienced in Algiers that accelerates the encapsulant browning failure mechanism.