Assessing the Balance Between Direct Electrification and the Use of Decarbonised Gases in the 2050 EU Energy System

If Europe is to meet its 2050 decarbonisation objectives, a change of paradigm needs to materialise. The energy sector cannot be understood any more as the sum of independent silos consisting of different energy vectors. Indeed, a large number of technologies that are essential to meeting our decarbonisation targets are linking systems and markets currently being planned and operated without fully considering the potential benefits of adopting a holistic approach. If this situation is to persist, large-scale sub-optimalities are likely to emerge if the planning and operations of the different components of the energy system will not be able to capture synergies and interdependencies between energy vectors and markets. Interlinkages between systems are appearing between all vectors, both at the planning and operation levels. In the case of hydrogen, these links are especially important, as hydrogen technologies are linking the electricity, methane and heat sectors (via electrolysis and hydrogen turbines, repurposing of gas assets, and hydrogen boilers, respectively). Sector integration can allow to capture benefits both in terms of planning and operations:- The production of electrolytic hydrogen poses important challenges in terms of planning the deployment of renewable energy (RES) and electrolyser capacities in a way that ensures that the overall carbon emissions decrease in an effective and cost-efficient manner. Furthermore, key questions related to the benefits of co-locating renewable capacities, electrolysers and hydrogen demand centres can only be explored if a holistic perspective is adopted. Finally, synergies can also appear if planning decisions are taken jointly between the electricity, hydrogen and methane sectors as the optimal set of hydrogen infrastructure projects strongly depends on the ability to source electrolysers (link with the electricity sector) and on the possibility to repurpose part of the current infrastructure (link with the methane sector)- Similarly, operational considerations also advocate for an integrated approach as electrolysers can provide important flexibility services to the electricity sector if provided with appropriate price signals. These considerations provide the motivation for this study, which aims at performing a detailed examination of planning decisions and operational management of a 2050 power system with a focus on comparing different decarbonisation options for the provision of heat of different temperature levels.