Time-space distribution analysis of Direct Solar Radiation in Nigeria

Abstract

ABSTRACT

Background: The paper utilizes data obtained from geostationary satellite platform to describe the seasonal and spatial distribution of direct solar radiation over Nigeria.

Objectives: The study aims to examine the geographical nature of direct solar radiation over Nigeria.   

Methods: All data were collected from the NASA Goddard Earth Observing System – Version 1 (GEOS-1) Multiyear Assimilation Time-series Data on the NOAA 17 satellite.

Results: Results show that direct solar radiation (DSR) increases in value from the Atlantic coast northwards, and is generally lower during the rainy season than the dry season. The northward increase was found to be almost parallel with lines of latitude although the contour lines are slightly skewed to a West-North-West to East-South-East orientation. Bivariate regression models show a direct relationship between direct solar radiation and latitude; clearness index; and an average elevation above sea level, whereas an inverse relationship is shown with daily cloud amount; average daily solar angle; and average daily relative humidity.

Conclusions: Spatial distribution of daily direct solar radiation is closely related to latitude. This understanding is useful for solar energy policy development in Nigeria.