Enhancing the ICON reanalysis dataset for energy‑sector applications within the MEDAILLON project

High-resolution meteorological data are essential for the energy sector because they are central for the design and operation of renewable‑energy systems. Existing data sets, however, exhibit shortcomings. Within the MEDAILLON project, the German Meteorological Service (DWD), in cooperation with Fraunhofer Institute for Energy Economics and Energy System Technology (IEE), the University of Kassel, and menzio GmbH, uses the ICON-DREAM reanalysis to develop a meteorological data set tailored for Germany’s energy sector. Potential stakeholders were consulted during the development phase to ensure the dataset meets their needs.

The meteorological dataset builds upon the ICON‑DREAM reanalysis – “ICON‑Dual‑resolution Reanalysis for Emulators, Applications and Monitoring” [1] – developed and produced by DWD based on the ICON numerical-weather-prediction (NWP) framework. ICON‑DREAM also includes a 20‑member ensemble for uncertainty assessment and is statistically processed to produce ensemble statistics such as mean, median, standard deviation, and min/max for each variable. Current data cover 2010 to July 2025 at hourly temporal resolution [2]. We aim to update the data continuously and extend the archive back to the 1980s.

To meet the specific needs of the German energy sector, we extract a national subset from the ICON‑DREAM‑EU domain. This subset is delivered at a spatial resolution of 6.5 × 6.5 km for the deterministic fields and at 20 × 20 km for the ensemble members. This contribution presents an evaluation of the reanalysis against parameters relevant to the renewable‑energy sector – such as wind speed and wind direction at hub height, radiation and temperature. The dataset will be released as an optimized, user‑friendly product, including uncertainty estimation from the ensemble. In accordance with the DWDs Open Data Policy the dataset will be provided free of charge. The evaluation draws on observational data and accounts for extreme events.

 

[1] Valmassoi, A., J. D. Keller, R. Potthast, H. Anlauf, A. Cress, F. Kaspar, and A. Becker: ICON-DREAM: the new dual resolution reanalysis from DWD. ICCARUS Book of Abstracts 2025. https://dx.doi.org/10.5676/DWD_pub/nwv/iccarus_2025

[2] Valmassoi, Arianna; Anlauf, Harald; Becker, Andreas; Keller, Jan D.; Krebber, Sibylle; Zängl, Günther; Potthast, Roland; Cress, Alexander; Fundel, Felix; Hanisch, Thomas; Lange, Martin; Steinert, Thorsten; Kaspar, Frank, "ICON-DREAM: ICON-Dual resolution Reanalysis for Emulators, Applications and Monitoring The ICON-Dual resolution reanalysis version v1.0." Deutscher Wetterdienst, 2025, doi:10.5676/dwd/icon-dream_v1.

Acknowledgement: This work was supported by the Federal Ministry for Economic Affairs and Energy through the Medaillon project (CNr: 03EI1059D).