Hourly Solar Radiation Estimation Using Ambient Temperature and Relative Humidity Data

This paper presents hourly solar radiation
estimation methods using ambient temperature and relative
humidity data. The methods are based on the decomposition
model that is calculating each of solar radiation components,
which depend on atmospheric transmittance. Two methods to
predict atmospheric transmittance value using available
meteorological data were proposed. In the first method, a
decision matrix was used, while in the second method,
regression correlation of meteorological parameters was used.
The calculations results were evaluated using statistical
parameter. Though the result shows both of the methods
perform well, more satisfactory results were obtained from first
method with Root Mean Square Error of 87.6 Watt/m2,
Normalized Root Mean Square Error of 8.29%, correlation
coefficient of 0.95 and index of agreement of 0.97. Furthermore,
the first method only needs ambient temperature and relative
humidity data that commonly measured in meteorological
stations.