The role of renewable fuels in a fossil-free European whole-energy system by Paolo Thiran

With the Green Deal, the European Union has committed to transitioning to a fossil-free energy system, and recent energy crises have highlighted the importance of energy sovereignty in Europe. Renewable fuels, derived from renewable biomass or electricity, have been identified as a critical vector for achieving this goal due to their versatility for many applications such as seasonal storage, energy transport, and potential use in hard-to-abate sectors. They are often referred to as the "Swiss Army Knives" of the energy transition. However, their production is expensive, and often less efficient than alternatives like direct electrification. Therefore, renewable fuels can be considered scarce and strategic resources, and experts have proposed criteria, such as the hydrogen ladder, to prioritize their use.

Despite their potential benefits, the integrated use of renewable fuels at the European scale has been little studied. This study addresses this gap by applying a multi-regional whole-energy system optimization model, EnergyScope Multi-Cells, to develop a fossil-free European energy system by 2050. This model considers all energy sectors and several energy carriers, enabling a direct comparison of renewable fuels with competing alternatives. We analyze the strategic use of renewable and provide guidelines on their quantities for key applications such as storage, the chemical industry, and energy exchanges within Europe. Furthermore, we analyze the origin of these fuels in the different scenarios: whether they are imported or produced in Europe, and the implications for energy sovereignty.

Overall, our study provides valuable insights into the strategic use of renewable fuels in a fossil-free European energy system. The guidelines and analyses we provide can inform policymakers, industry stakeholders, and researchers in their efforts to promote sustainable and secure energy systems.