Sensitivity Analysis of Radiation Schemes in WRF-Solar for SolarEnergy Applications in Senegal

Solar irradiance forecasting plays a pivotal role in maximizing the use of solar energy resources and promoting the transition towards a cleaner and more sustainable energy future. This study evaluates the performance of the Weather Research and Forecasting (WRF-Solar) model using two shortwave radiation schemes in estimating Global Horizontal Irradiance (GHI) at two solar power plants in Senegal, i.e. Diass and Ten Merina. The different simulation experiments of WRF-Solar are specifically assessed under different sky conditions using hourly GHI measurements for 2020 from the solar plants operated by energy companies in Senegal. A total of six simulations are performed using different shortwave radiation schemes (Dudhia and RRTMG). There are two simulations run for the RRTMG scheme: one without aerosol optical depth (AOD) and one with AOD (RRTMG_AOD). In addition, the impact of shallow convection on the model performance is investigated. Results indicate that the RRTMG_AERO scheme outperforms other schemes with the highest correlation of 0.85 and the lowest values of RMSE (160 W/m2) and MAE (110 W/m2). It shows superior performance across clear, cloudy, and all-sky conditions. While the inclusion of shallow convection has minimal impact on GHI estimation accuracy under clear skies, some differences are noted under cloudy conditions at Ten Merina. Notably, the model shows biases, particularly under cloudy skies. These findings offer valuable insights that can enhance solar energy forecasting accuracy, support reliable solar power generation and renewable energy optimization, benefiting energy providers, policymakers and communities in Senegal.