TITLE:
Estimation of Global Solar Radiation for Four Selected Sites in Nepal Using Sunshine Hours, Temperature and Relative Humidity
AUTHORS:
Krishna R. Adhikari, Binod K. Bhattarai, Shekhar Gurung
KEYWORDS:
Global Solar Radiation; Clearness Index; Sunshine Hours; Linear Regression Relation; Model
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.1 No.3,
September
27,
2013
ABSTRACT: Rational and accurate solar energy databases,
essential for designing, sizing and performing the solar energy systems in any
part of the world, are not easily accessible in different localities of Nepal.
In this study, daily global solar radiation, sunshine hours and meteorological
data for Biratnagar, Kathmandu, Pokhara and Jumla have been used to derive the
regression constants.
The linear regression technique has been used to develop a model for
Biratnagar, Kathmandu, Pokhara and Jumla. The model has calculated the global
solar radiation for these locations. The values of global solar radiation
estimated by the model are found to be in close agreement with measured values
of respective sites. The estimated values were compared with Angstrom-Prescott
model and examined using the root mean square error (RMSE), mean bias error
(MBE), mean percentage error (MPE), coefficient of regression (R), coefficient
of determinant (R2) and correlation coefficient (CC) statistical
techniques. Thus, the resultant correlations and linear regression relations
may be then used for the locations of similar meteorological/geographical
characteristics and also can be used to estimate the missing data of solar
radiation for the respective site.