This repository includes input data to run the model PyPSA-Eur-Sec-30-paths and the results discussed in the paper "Early decarbonisation of the European energy system pays off" The code to run the model can be found in the Github repository PyPSA-Eur-Sec-30-paths and the permanent repository 10.5281/zenodo.4014807 The directory 'data/' includes all the datasets needed to run the model. The directories 'version-*/' include the network objects obtained as an outcome of the optimization in the different scenarios. The directory 'summaries/' includes summaries with the most relevant aggregated results. All input data (in the directory 'data/') and results (in the directories 'version-*/' and 'summaries/') are released under the Creative Commons Attribution 4.0 International Licence (CC BY 4.0), except those where explicit sources and licences are mentioned in the data folders.