Modelling a highly decarbonised North Sea energy system in 2050: A multinational approach

The North Sea region, located in the Northwest of Europe, is expected to be a frontrunner in the European energy transition. This paper aims to analyse different optimal system configurations in order to meet net-zero emission targets in 2050. Overall, the paper presents two main contributions: first, we develop and introduce the IESA-NS model. The IESA-NS model is an optimization integrated energy system model written as a linear problem. The IESA-NS model optimizes the long-term investment planning and short-term operation of seven North Sea region countries (Belgium, Denmark, Germany, the Netherlands, Norway, Sweden and the United Kingdom). The model can optimize multiple years simultaneously, accounts for all the national GHG emissions and includes a thorough representation of all the sectors of the energy system. Second, we run several decarbonisation scenarios with net-zero emission targets in 2050. Relevant parameters varied to produce the scenarios include biomass availability, VRE potentials, low social acceptance of onshore VRE, ban of CCUS or mitigation targets in international transport and industry feedstock. Results show a large use of hydrogen when international transport emissions are considered in the targets (5.6 EJ to 7.3 EJ). Electrolysis is the preferred pathway for hydrogen production (up to 6.4 EJ), far ahead of natural gas reforming (up to 2.2 EJ). Allowing offshore interconnectors (e.g. meshed offshore grid between the Netherlands, Germany and the United Kingdom) permits to integrate larger amounts of offshore wind (122 GW to 191 GW of additional capacity compared to reference scenarios), while substantially increasing the cross-border interconnection capacities (up to 120 GW). All the biomass available is used in the scenarios across multiple end uses, including biofuel production (up to 3.5 EJ), high temperature heat (up to 2.5 EJ), feedstock for industry (up to 2 EJ), residential heat (up to 600 PJ) and power generation (up to 900 PJ). In general, most of the results justify the development of multinational energy system models, in which the spatial coverage lays between national and continental models.