Temperature – Induced Variations in the Electrical Performance of Three Polycrystalline Photovoltaic Modules under Afaka Climatic Conditions, Kaduna, Nigeria

Abstract

The performance of photovoltaic (PV) modules is strongly influenced by environmental conditions, particularly temperature. This study investigated the effect of temperature on the electrical performance of three commercially available 80 W polycrystalline photovoltaic modules installed under the climatic conditions of Afaka, Kaduna, Nigeria. Measurements were conducted over a 151 – day period during the dry season using hourly observations of ambient temperature, Module Temperature, relative humidity, open – circuit voltage (Voc), and short – circuit current (Isc). Daily global radiation data were obtained from the Nigerian Meteorological Agency (NiMet).

Results showed that ambient temperature varied between approximately 24 °C and 40 °C, while Module Temperature frequently exceeded ambient temperature and reached values above 45 °C during periods of intense solar radiation. Relative humidity decreased substantially during the hottest periods, creating conditions that intensified thermal loading of the modules. Short – circuit current exhibited a positive response to increasing solar radiation, whereas open - circuit voltage decreased as Module Temperature increased. Correlation analysis revealed a strong positive relationship between Module Temperature and ambient temperature (R² = 0.8583) and a strong inverse relationship between ambient temperature and relative humidity (R² = 0.8772). These environmental interactions contributed significantly to variations in module electrical behaviour throughout the monitoring period.

Among the modules investigated, Sample A produced the highest short – circuit current, while Sample C consistently exhibited the highest open – circuit voltage. The findings demonstrate that temperature is a major factor affecting photovoltaic module electrical performance under northern Nigerian climatic conditions and highlight the importance of thermal considerations in photovoltaic system design and module selection for hot environments.