Abstract

Lack of incident solar radiation is a significant impediment for most related research applications. Mathematical models have been handy in reducing challenges being posed by inability of having solar radiation instrumental sites at every point on the Earth. Hargreaves-Samani’s model is one of the several empirical methods so far formulated in estimating global solar radiation (GSR) from maximum and minimum temperature data. Most of these models are often been applied in mid-latitudes. The paper attempts to assess the performance of Hargreaves-Samani’s model in the Savanna region using Abuja as the case study. Estimated values of GSR from one month data adapted from Nigeria meteorological Agency (NIMET); using Hargreaves’ model shows 90% index of agreement (IA) with the observed values; which suggests a good model performance that has significant correction of about 29%. Concepts are suggested on improving the model performance in the savannah region.

Key words: Global Solar radiation, air temperature, model validation, inversion-layer.