The EU Copernicus Climate Change Service (C3S) has produced an operational climate service, called C3S Energy, designed to enable the energy industry and policy makers to assess the impacts of climate variability and climate change on the energy sector in Europe. The C3S Energy service covers different time horizons, for the past forty years and the future. It provides time series of electricity demand and supply from wind, solar photovoltaic and hydro power, and can be used for recent trends analysis, seasonal outlooks or the assessment of climate change impacts on energy mixes in the long-term. This paper introduces this dataset, with a focus on the design and validation of the energy conversion models, based on ENTSO-E energy data and the ERA5 climate reanalysis. Flexibility and coherence across all countries have been privileged upon models’ accuracy. However, the comparison with ENTSO-E data shows that the models provide plausible energy indicators and, in particular, allow to compare climate variability effects on power demand and generation in an homogenous approach all over Europe.