Estimation of global solar radiation on horizontal surface in Erzincan, Turkey

Abstract

In the applications of solar energy, the solar radiation data and their components in a region must be known for the design of a system. In the locations where no solar radiation data is available, this parameter can be determined by performing a reasonable correlation. In the study, the models of global solar radiation on the horizontal surface in the literature are investigated, and new empirical models based on the sunshine hour data for Erzincan, Turkey are developed. In order to indicate the performance of the models, the statistical test methods of mean bias error (MBE), root mean square error (RMSE) and mean relative error (MRE) are used. The results obtained indicate that the correlations developed in the study predict the global solar radiation reasonably well for the future projections.

Global Solar Radiation Studies Due to Sunshine Hours and Other Meteorological Parameters

“…It is possible to have a large RMSE value and at the same time a small MBE (a large scatter about the line of perfect estimation). On the other hand, it is also possible to have a relatively small RMSE and a relatively large MBE (a consistently small over-or underestimation) (Khan and Ahmad, 2012). Figure 1 shows plots of Equation (7) with the least value of RMSE together with the monthly average daily sunshine hours measured for eleven years.…”

“…One of the earliest correlations was proposed as far back as 1924 by Angstrom and relates global solar radiation to hours of bright sunshine. Several empirical models have been developed to calculate global solar radiation using various parameters (Umoh and Udoh, 2010;Akpan and Umoh, 2011a;2011b;Khan and Ahmad, 2012;Ahmed and Hussein, 2012;Jakhrani et al, 2013;Kaya, 2012;Al-Dulaimy et al, 2010). The parameter used as input in the calculations include, sunshine duration, Mean temperature, soil temperature, relative humidity, number of rainy days, altitude, latitude, total perceptible water, albedo, atmospheric pressure, cloudiness and evaporation.…”

Modelling of Solar Radiation for Photovoltaic Applications

“…To ascertain the accuracy of the models, some statistical tools for the evaluation of the models have been presented. These include the mean bias error (MBE), the root mean square error (RMSE) and t-statistics [3][4][5]. A. S. Angstrom [3] disclosed that these statistical tools collectively combine to establish the consistency of the models.…”