Evaluation of McClear Clear Sky Model under Dusty Conditions

Clear-sky models play a crucial role in simulating solar radiation at the Earth's surface under cloudless conditions, with applications in several areas. For instance, clear-sky models help determine the maximum potential output of solar energy systems and calculate atmospheric indices which measure the atmospheric clarity and turbidity. In addition, these models are crucial for estimating the solar radiation from satellite images, providing the upper limits for irradiance under clear-sky conditions, before considering the cloud modelling. Clear-sky models also support quality control of solar data and can be used as reference to validate other models, such as transposition and decomposition models under clear-sky scenarios. A wide range of clear-sky models are described in scientific literature. This work examines commonly used clear-sky models for solar resource assessment, focusing on their performance in a region characterized by high aerosol concentrations. Specifically, the McClear model is compared to the Simple Model for the Atmospheric Radiative Transfer of Sunshine (SMARTS-2), and the European Solar Radiation Atlas (ESRA) model. The evaluation is conducted using days with varied aerosol content, including instances of significant atmospheric dust. Sun photometer aerosol-derived data and ground-based solar radiation measurements are used as inputs and to assess the performance of the models, respectively.