SOURCE:

Faculty: Physical Sciences
Department: Physics And Industrial Physics

CONTRIBUTORS:

Elekalachi, C. I.
Nwokoye, A. O. C.

ABSTRACT:

Global solar radiation is an important parameter necessary for most ecological models and serves as input for different photovoltaic conversion systems. Hence it is of economic importance to renewable energy alternative. In this study, we have employed the linear regression model of Angstrom (1924) and Page (1964) for these analyses to correlate the global solar radiation data with relative sunshine duration, relative humidity and maximum temperature for 3 cities (sites) in each of the six geopolitical zones in Nigeria, which gives a total of 18 sites. Other multiple linear regression models were obtained to check the correlation of global solar radiation with sunshine duration combined with other meteorological parameters which include maximum temperature and relative humidity. These meteorological parameters used for this work were obtained from the archives of National Aeronautics and Space Administration (NASA) for the time period of 11 years from 2000 to 2010. The results obtained were statistically tested using four statistical error indicators; Mean Bias Error (MBE), Root Mean Square Error, (RMSE), Mean Percentage Error (MPE) and t-stat to establish the validity of the results. The analyses show that there is close correlation between the calculated mean global solar radiation and the estimated global solar radiation using our established models, though some models correlate better than others. The best empirical equation for each of the sites was evaluated based on the values of the t – stat. 𝐻3 is the best model for Awka with t – stat value of 0.050. 𝐻1 is the best model for Enugu with t – stat value of 0.045. 𝐻5 is the best model for Owerri with t – stat value of 4.692. 𝐻3 is the best model for Calabar with t – stat value of 0.0327. 𝐻3 is the best model for Port – Harcourt with t – stat value of 0.0830. 𝐻1 is the best model for Asaba with t – stat value of 0.0126. 𝐻5 is the best models for Lagos with t – stat value of 0.00259. 𝐻5 is the best model for Akure with t – stat value of 0.0232. 𝐻5 is the best model for Ado – Ekiti with t – stat value of 01.166. 𝐻5 is the best model for Gombe with t – stat value of 0.0361, 𝐻1 is the best model for Yola with t – stat value of 0.056. 𝐻3 is the best model for Maiduguri with t – stat value of 0.0359. 𝐻1 is the best model for Abuja with t – stat value of 0.0882. 𝐻1 is the best model for Minna with t – stat value of 0.281. 𝐻3 is the best model for Ilorin with t – stat value of 0.00148. 𝐻3 is the best model for Gusau with t – stat value of 0.0184. 𝐻2 is the best model for Kano with t – stat value of 0.0112. 𝐻5 is the best model for Birnin – Kebbi with t – stat value of 0.0338.