Mono-crystalline and Poly-crystalline Photovoltaic Modules Performance under Ambient Condition of Dodoma, Tanzania

Abstract

Photovoltaic (PV) modules are rated based on the Standard Test condition (STC). However, real-time performance under ambient conditions differs from performance reported by manufacturers. In this paper, the electrical performance of mono-crystalline(m-Si) and poly-crystalline(p-Si) installed 25 m at the rooftop building at University of Dodoma in Tanzania are presented. Results show that electrical parameters for each PV module strongly depend on the ambient parameters under consideration. At lower solar irradiance (below 400W/m2) and lower module temperature (below 25°C), all PV module parameters were found to increase with increasing solar irradiance and module temperature. However, at higher solar irradiance and elevated module temperature, PV module parameters except the current showed a decreasing trend with increasing solar irradiance, module temperature, and relative humidity. In comparison, m-Si with a normalized power output of 78% under ambient conditions is slightly better than p-Si which exhibits 73%.