Validation of HelioClim-3-Derived Solar Radiation Products in Arid Desert Conditions

Solar resources are crucially needed for the deployment and operation of solar energy projects. Ground measurements of solar radiation are the best way to obtain accurate solar resource data, especially when they are acquired with a well-designed and maintained monitoring station. When ground data are not available, satellite-derived solar resources present a viable alternative, as they can provide data with wide spatial and temporal coverage, i.e., historical solar data for as many locations as covered by the satellite images. However, the accuracy of the satellite model should be determined in order to use the derived data correctly. In this contribution, we present an assessment of the HelioClim-3 version 5 (HC3v5) database from SoDa, including the comparison of the 15-min, hourly, and daily estimated global horizontal (GHI), direct normal (DNI), and diffuse horizontal (DHI) irradiations against ground measured data at two distinct sites located in Qatar. Considering the different years and the two locations, the average correlation coefficients are for the global irradiation 0.93 (15-min), 0.95 (hourly), 0.93 (daily), for the direct irradiation 0.67 (15-min), 0.73 (hourly), 0.8 (daily), and for the diffuse irradiation 0.69 (15-min), 0.73 (hourly), 0.81 (daily). The errors in terms of relative biases and root mean square errors are lower for the global component and for the coastal site. In general, HC3v5 tends to underestimate the irradiations with lower performance at the inland site, characterized by higher aerosol loads.