Evaluation of various global solar radiation models for Nigeria

Abstract

This study assessed the performance of six solar radiation models. The objective was to determine the most accurate model for estimating global solar radiation on a horizontal surface in Nigeria. Twenty-two years meteorological data sets collected from the Nigerian Meteorological agency and the National Aeronautics and Space Administration for the three regions, covering the entire climatic zones in Nigeria were utilized for calibrating and validating the selected models for Nigeria. The accuracy and applicability of various models were determined for three locations (Abuja, Benin City, and Sokoto), which spread across Nigeria using seven viable statistical indices. This study found that the estimation results of considered models are statistically significant at the 95% confidence level, but their accuracy varies from one location to another. However, the multivariable regression relationship deduced in terms of sunshine ratio, air temperature ratio, maximum air temperature, and cloudiness performs better than other relationships. The multivariable relationship has the least root mean square error and mean absolute bias error, not exceeding 1.0854 and 0.8160 MJ m −2 day −1 , respectively, and monthly relative percentage error in the range of ± 12% for the study areas.

Calibration of Ångström-Prescott Equation to Estimate Daily Solar Radiation on Rio Grande do Norte State, Brazil

“…The calibration and application of Ångström-Prescott equation has been performed in numerous regions of the world (Almorox et al, 2005, Liu et al, 2009Rahimi et al, 2012;Khorasanizadeh and Mohammadi, 2013), including tropical zones (Belúcio et al, 2014;Okundamiya et al, 2016). The results obtained in these studies shown a satisfactory performance of the calibrated Ångström-Prescott equation relatively to observations.…”

Models for Calculating Monthly Average Solar Radiation from Air Temperature in Swaziland

“…In addition, the performance of the models can be quantified by evaluating the root-mean-square-error (RMSE) and the mean-percentage-error (MPE). These are fundamental measures of accuracy in solar energy calculations (Saffaripour, 2013;, Muzathik, 2011Okundamiya, 2016). They are respectively defined as ( ) Where n=12 is the number of data pairs, calc j H , is the j-th calculated value and meas j H , is the j-th measured value.…”

“…There are also intermediate models that require the input of two or more inputs of meteorological parameter (Okundamiya, 2016).…”

A critical review of theoretical models for estimating global so-lar radiation between 2012-2016 in Nigeria

“…In this group, clearness index is correlated to non-linear sunshine duration (S) relation as a modification from Angstrom-Prescott type model in the form: (50) Okundamiya et al [47] estimated the following MB model for Benin City.…”

“…In this group, sunshine duration, temperature and cloud were incorporated with clearness index for estimating global solar radiation in the form: (126) Okundamiya et al [47] developed the following MB model for Benin City as: (127) …”