THE EFFECTS OF SOLAR IRRADIANCE AND AMBIENT TEMPERATURE ON SOLAR PV MODULE OUTPUT IN NORTHERN GHANA

Abstract

Solar energy is abundant It is however low grade energy and cannot be easily used in the form it occurs for work. Converting solar energy directly to electricity, using solar photovoltaic (PV) modules is however a low efficiency process. Optimizing this conversion, especially in the face of the high cost of solar panels, is thus desirable. Towards this end, it is necessary to know the maximum output periods of solar modules and the conditions for maximum panel output. This paper is the result of a study of the effects of solar irradiance and ambient temperature on the output of solar PV modules. In this study, using polycrystalline and amorphous silicon PV panels - the most widely used in the Northern, Upper East and Upper West regions, the output current and voltage from the solar panels (PV modules), and hence the output power, were measured at hourly intervals of time. The corresponding temperature at each reading was also recorded This was carried out in the dry season and in the rainy season. From analysis of the results, it was found that the times of high charging current, and that is the best time to put out the solar panels for charging is between 9:00 am to 11:00 am on sunny days. On cloudy days, charging should he extended to the evening. With regards to irradiance and temperature, it was found that for both types of panels, the output depended a lot on irradiance. Ambient temperatures above 30°C cause a slight (5 - 9%) decrease in output. Thus, the study shows that high irradiance, coupled with temperatures between 26°C - 30°C are necessary for high panel output.