Modelling the interactions between power systems and energy systems

The European Union has significant ambitions to decarbonise the energy system by 2050. The power system is expected to play a key role in this energy transition, with this role involving increased electrification of heat and transport and increased integration of variable renewable electricity. Energy systems models are currently used to inform long-term policy decisions, generating technology pathways for energy system decarbonisation. However, they struggle to sufficiently represent short term characteristics of power system operation, which can lead to over simplified conclusions and misguided policy decisions. The core aim of this thesis is to use a multi-model approach to improve this representation of short-term power sector operation in long-term energy system planning with a view to gaining a better understanding of the role of electricity in the wider European energy system decarbonisation. The thesis links detailed operational power systems models to a number of long-term energy planning models and energy planning studies. This leverages the strengths of a heavily interconnected pan-European dispatch model with high technical and temporal resolution. The thesis generates new results and insights that energy systems models struggle to provide, such as interconnector congestion, renewable electricity curtailment and electricity market prices. It also explores the impact of inter-annual wind and solar variations on the future EU power system. It further proposes an approach to determine the renewable electricity share for each Member State based on renewable electricity consumed rather than produced, accounting for international flows of electricity on an hourly basis. Detailed power systems modelling coupled with long-term energy system planning is shown to allow for sectoral nuances, such as individual generator constraints and flexibility, to be captured which allows for balanced assessment of policy. The key contributions of this thesis are both the methodological gains and the operational power sector insights attained which when combined allow for better projection of technology pathways for the energy system and more effective energy policy formulation