Abstract:
This research work is aimed at estimating solar radiation using surface temperature and sunshine
duration for Gusau, Abuja and Ikeja.
The global solar radiation on horizontal surface at the location of interest is the most critical input
parameter employed in the design and prediction of the performance of solar energy devices. In
spite of its importance, its measurements are not frequently available especially in developing
countries. From maximum, minimum temperatures, sunshine hour and monthly mean global
radiation data for Gusau, Abuja and Ikeja, for a period of 1980 – 2010, ten (10) correlation
equations from univariable and multivariable Angstrom’s type equations have been produced for
the years and the periods of dry and wet seasons. Four (4) other models were also tested for to see
the best performer with the estimated global radiation. From these, it was deduced that the Glower
and Mcgulloch model has the overall best performance according to MBE and RMSE values for
all the stations. More so, the equations combining temperature parameters performed best for
Ikeja, Gusau and Abuja in that order, while the models performed best for Gusau, Abuja and Ikeja
in that order. It was also noticed that the coefficients of correlation and determination were lower
for the wet (rainy) season than the dry season for Gusau and Ikeja which is in agreement with the
work of (Okogbue and Adedokun, 2002) for Ondo, while higher values were noticed for the wet
season than dry season for Abuja which is in conformity with the work of (Okundamiya and
Nzeako, 2009). This implies that estimation of solar radiation depends more on those parameters
in the dry season than in the wet season for Gusau and Ikeja while depending more on the
parameters in the wet season for Abuja, and more so, the estimation of solar radiation is seasonal
dependence.
