Assessment of solar radiation models for the Gulf Arabian countries

A statistical assessment of the accuracy of 12 solar radiation models for five meteorological stations in the Gulf Arabian states namely Abu Dhabi, Bahrain, Doha, Kuwait and Riyadh, is presented. The first six models are of the regression type in which the measured global radiation is correlated with the sunshine hours and other meteorological parameters. The other six models are based on the calculation of clear sky radiation and the effects of cloud amount and sky transmittance. The models are assessed in terms of the root mean square error and the mean bias error. The obtained results indicate some inconsistency of published data for Abu Dhabi, Bahrain and Doha stations. However, using Kuwait and Riyadh stations as a basis for the evaluation, two models are recommended for the estimation of monthly average daily and hourly global radiation for the Gulf states.