How Complex Are Satellite-Based Irradiation Data? From Global Averages to Location-Specific Accuracy

3E irradiation data is a service that provides satellite-based solar resource data. These data are derived from meteorological geostationary satellites using the Cloud Physical Properties (CPP) algorithm developed by the Royal Dutch Meteorological Institute. While it is demonstrated that the accuracy of such data varies strongly depending on the location, global average numbers are still often applied in long-term yield assessments and solar plant performance analyses. We aim to change that by systematically studying the factors that impact this accuracy. Using a dedicated validation framework, we benchmark our satellite-based data against more than 900 ground measurement sites worldwide. We then combine these results with statistical models to identify which complexity factors matter most and to predict the expected accuracy at any given location. The outcome is a set of global maps of accuracy, providing transparency on how reliable satellite-based irradiance data are, wherever you are on Earth.