The JRC-EU-TIMES is a partial equilibrium energy system model maintained by the Institute for Energy and Transport (IET) of the Joint Research Centre (JRC) to analyse the role of energy technologies development and their potential contribution to decarbonisation pathways of the energy system. The technical potentials for renewable energies are a key input in models of this kind. In this context, it is important to ensure transparency in the assumptions: making available the underlying data to the public is thus an important step that can also further contribute to a scientific and transparent debate. This report is the first in a series on renewable energy potentials, and addresses the quantification of current and future biomass potentials for energy systems.As already identified in the 2011 European Commission’s Communication Energy roadmap 2050, biomass is expected to play a key role in strengthening the Energy Union pillars by diversifying the energy supply, increasing the energy internal market, decarbonising the economy and boosting competitiveness. To fully understand the implications of an increased use of biomass for energy, updated data on technical potentials available in EU countries is needed.Building on the initial efforts from the European Environment Agency that were followed by key projects like BEE and Biomass Futures, this report presents the results of extending and improving current methodologies on renewable potentials evaluation. The resulting framework is applied to obtain estimations fit to respond to energy system modelling needs, while extending the projections to 2050 and assessing the effect of sustainability scenarios on future available biomass. The sets of data produced are input to the JRC-EU-TIMES model to analyse the main drivers of future biomass use within the energy systems.