Statistical Comparison of Models for estimating Solar Radiation on
Inclined Surfaces
Solar Energy, 31 (3):
313--317 (1983)Abstract
The objectives of this study are to compare statistically three models
for estimating solar radiation on inclined surfaces and to recommend
one that is general and accurate. The isotropic model, and Klucher?s
and Hay?s anisotropic models are chosen for discussion. The hourly
and daily formulations of these models are briefly described. Results
show that they all produce large errors at steep slopes. The errors
are minimum during the summer months. The isotropic model under-estimated
consistently throughout the year resulting in the worst performance.
Hay?s model also under-estimated constantly but by a smaller amount.
Klucher?s model overestimated in the summer and under-estimated in
the winter, but can be considered just as general and accurate as
Hay?s model for estimating insolation on inclined surfaces.