Towards a Solar Resource Atlas for Poland (AES-PL): high-resolution assessment of PV potential, variability, and local energy droughts from satellite data

Detailed characterization of solar energy resources is increasingly needed to guide national and regional energy transition strategies, support grid planning, and reduce uncertainty for investors. Yet in many European countries the spatial and temporal resolution of publicly available solar datasets remains insufficient for detailed planning. In Poland this gap is further amplified by the limited number of actinometric stations, which makes ground-based climatological series spatially incomplete and unsuitable for characterizing finer temporal dynamics relevant for modern power systems.

To address this, we introduce the concept of the Solar Energy Atlas for Poland (Atlas Energetyki Solarnej PL; AES-PL) - a new high-resolution atlas derived from satellite-based LandSAF products. The atlas provides continuous solar resource data for the period 2015–2024, with 15-min temporal resolution and 3 km spatial resolution, covering the entire territory of Poland. From these data we derive core irradiance metrics (GHI, DNI, GTI) and compute usable PV resource indicators including energy yield (kWh/kWp), capacity factor, and characteristic diurnal profiles for the nine tilt–azimuth configurations most relevant to PV deployment in Poland.

Beyond standard resource climatology, AES-PL explicitly addresses temporal variability as a key dimension of the energy transition. This includes: intra-day variability using a satellite-based ramp-rate metric; inter-annual variability from 10-year continuous time series, and local identification of solar energy droughts understood as prolonged periods of below-median solar input affecting PV production and system balance. Identifying such droughts is important for evaluating system adequacy, storage needs, and interactions with other variable renewables such as wind.

The atlas thus responds to several emerging needs: for system operators, to assess variability, forecastability, and operational flexibility requirements, for investors, to reduce resource and revenue uncertainty at the feasibility study stage, for planners and regulators, to support spatial planning, auction design, and grid reinforcement strategies, and for researchers, by providing an openly documented dataset suitable for integration into energy system models.

By bridging the gap between ground-based point measurements and national policy needs, AES-PL aims to provide a transparent, spatially continuous, and reproducible resource that supports evidence-based decision-making in the context of Poland’s accelerating energy transition.