Satellite-Derived Irradiance Data for PV Performance Assessments in High Latitudes

The rapid adoption of photovoltaic (PV) systems in Nordic countries, has made accurate performance evaluation increasingly important. In Finland, microgenerators below 1 MW now collectively exceed 1 GW, and large-scale PV plants are being considered as part of the national energy strategy. Reliable performance assessments help verify energy yield, identify operational issues, and support planning for future installations. A key challenge is the limited availability of high-resolution meteorological data. Ground-based measurements are sparse and often located far from PV sites, reducing their usefulness for site-specific analysis. Satellite-derived solar radiation data offers a promising alternative, but its accuracy can be affected by latitude. Above 60° N, where many Finnish PV systems are located, geostationary satellite coverage becomes less precise, potentially introducing bias. This study evaluates the suitability of EUMETSAT’s CMSAF SARAH-3 data for PV performance modelling in Finland. Multi-year PV production data from several sites is compared against simulations using both satellite-derived and ground-station datasets. Results indicate that SARAH-3 achieves good agreement with measured data with coefficient of determination above 0.9 for global horizontal irradiance, suggesting it can serve as a reliable alternative where ground data is unavailable, enabling improved PV performance monitoring and planning in high-latitude regions.