COMPARATIVE STUDY OF THE ATMOSPHERIC PARAMETER-BASED MODELS FOR ESTIMATING GLOBAL SOLAR RADIATION OVER SOME SELECTED TROPICAL STATIONS.

Ojo, M.O* ,  Sanusi, Y.K and Owoyemi S.I**

 

*Department of Physics, Adeyemi College of Education, Ondo.

** Department of Physics, Adeyemi College of Education, Ondo.

Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso.

Abstract

Solar radiation is the principal and fundamental energy for many physical, chemical and biological processes. Despite its importance, it is measured at a limited number of stations in the tropical area. Therefore, estimation of solar radiation from the measured atmospheric variables offers an important alternative in the absence of measured solar radiation. In this study, five (5) atmospheric parameter-based models were developed and comparatively studied, using 11 year data obtained from the Archives of Nigerian Meteorological agency, Lagos and Atmospheric Science data centre of National aeronautic and Space administration, Abuja.  The models were assessed to estimate the global solar radiation over the horizontal surface of the tropical stations. The accuracy of the models was assessed using MBE, MPE, RMSE, R2 , MABE, AIC and SBC. The statistical analysis conducted showed that the atmospheric parameter-based models developed were well suited accurately for assessment and estimation of solar radiation potential. Based on the validation of the models, cubic model showed the best regression fit and performed slightly better than others with (R2 ranges between 0.150 - 0.407; r, ranges between 0.725 -0.996; RMSE ranges between 0.049 – 0.569; MABE ranges between 0.0377 – 0.0472; MBE ranges between -0.017 to 9.675, AIC ranges between -62.762 to -66.895 and SBC ranges between -31.488 to -34.625). The values of different global solar radiation produced by the atmospheric parameter –based models can be utilized in the analysis, design and performance evaluation of solar energy conversion systems.