Improving the solar resource estimation in the United Arab Emirates using aerosol and irradiance measurements

A locally-adapted model to predict irradiance in the United Arab Emirates (UAE) has been developed. It is based on the McClear model and the HelioClim database, and it utilizes aerosol optical depth measurements from AERONET network, and high-precision measurements of irradiance collected at Madinat Zayed, UAE. The clear-sky part of the model consists of McClear model operated with ground-corrected Aerosol Optical Depth (AOD) as inputs. The all-sky part is made of HelioClim-3, recalculated with the AOD-corrected McClear as inputs, and then calibrated using irradiance measurements at one station. The locally-adapted model accurately estimates the global and direct irradiances. The estimated irradiances have been validated against measurements collected from 7 Rotating Shadowband Irradiometers distributed over the UAE. The obtained root mean square errors on the hourly means of irradiance are 4% for Global Horizontal Irradiance (GHI), 10% for Direct Normal Irradiance (DNI) in cloudless skies and 8% for GHI, 26% for DNI in cloudy skies.