Optimising a Fully Renewable European Energy System Seizing the Flexibility of Gas and Heat Storage Systems

Abstract

Fully decarbonised energy systems are a cornerstone of reaching the agreed-upon global warming limitation goal in the Paris Agreement. A key feature of these energy systems will be the integration of the electricity, gas, heat and transport sectors. In this realm many questions are left unanswered, which are also under current debate in Germany, e.g. how electrification and the use of green synthetic fuels can work together to achieve climate neutrality. To be able to shed some more light on these questions, we are presenting a sector-integrated linear optimisation model of the European energy system within the modelling framework REMix. The model is resolved to 70 regions, contains more than 70 technologies, and optimises the capacities and hourly operation of all assets. A special focus is put on the flexibility options in the heat sector, where we are making use of heat groups to represent different temperature levels and application areas in buildings, industry and the district heating grid. Our results indicate that the electrification of the heat sector can cater for the majority of future demand if it is accompanied by the build-up of thermal storage capacities in buildings and the industry. Another important measure to achieve a cost-optimal energy system are large-scale hydrogen caverns that act primarily as seasonal storage. Finally, also the repurposement of natural gas to hydrogen pipelines from regions with high renewable potential to demand centres and storage sites is an important aspect to minimise overall system costs.