Advancing Solar Resource Data: the Validation Journey of 3E's Satellite-Based Irradiation Data

In 2016, 3E introduced its satellite-based irradiation data source. It uses a model that considers the physical properties of clouds, developed and operated by our partner the Royal Dutch Meteorological Institute (KNMI), to provide highly accurate satellite-based irradiation data, even at sub-hourly time resolutions. Today, 3E offers worldwide near-real-time and historical satellite-based irradiation data, based on four satellite series. These data are used for long-term yield assessments of photovoltaic systems, as in our 3E SynaptiQ Project Development solution, and performance analysis of existing photovoltaic systems, as in our 3E SynaptiQ Asset Operations and Solar Analytics solutions. For all these applications, data accuracy is essential and must be accounted for. It is why we take data validation seriously: a permanent internal validation framework is set up. It is based on measurements from public meteorological stations and focuses on the bias error and prediction error calculation. The bias error is close to zero, i.e. 0.3% and 0.7% for the global and European stations. The absence of bias combined with a low bias uncertainty, makes 3E’s satellite-based service a bankable source of irradiation data for long-term yield assessments of photovoltaic systems. On the other hand, the prediction error for hourly resolution data is limited to 17.2% and 17.4% for the global and European stations, which makes 3E’s satellite-based service a trustworthy data source for performance monitoring and reporting of photovoltaic systems.