Performance Assessment of Polycrystalline Silicon Pv Modules in Low Latitude Regions as A Function of Temperature
P.E. Ugwuoke, C.E. Okeke

Abstract
The performance of any PV module is directly proportional to the solar irradiance impinging on its surface and having enough energy capable of releasing electrons from the valence level to the conduction level of the cells of the module. It has been observed that module performance is significantly hampered by thermal stress due to temperature variations during operation under natural environment. A one-year performance characteristics of a 50-Watt polycrystalline silicon PV module as a function of temperature at Nsukka in Nigeria (Lat. 60 52′) was evaluated and reported in this paper. Significant decrease in efficiency Eff, maximum voltage Vmax, open-circuit voltage Voc and fill factor FF was noticed with increase in the module temperature at irradiances above 600 W/m2 while maximum current Imax and short-circuit current Isc showed no noticeable effect of the module temperature rise. At an irradiance of 1000W/m2 and a module temperature of 450C, the maximum power output of the module was observed to be 28.84 Watts, which is approximately 58 % of the manufacturer’s specification. The module performance ratio (MPR) at irradiance of 600W/m2, defined as the ratio of effective efficiency to the efficiency at standard test condition (STC), was observed to be 76.75% and decreased appreciably to 60.71% at 1000W/m2.

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