Investment decisions in a liberalised energy market with generation and hydrogen-based vector coupling storage in Integrated Energy System: A game-theoretic model-based approach

Meeting carbon reduction targets and enhancing energy supply flexibility necessitate the integration of natural gas and electricity networks, coupled with increased adoption of renewable energy. Bidirectional hydrogen- based Vector-Coupling Storage (VCS) offers a promising avenue for efficiently utilising surplus power from renewables, linking hydrogen as an energy carrier and storage with the Integrated Energy System (IES). This paper introduces a game-theoretic planning model for IES, encompassing natural gas, electricity, and independent VCS participants in a liberalised market. A game-theoretic model for capacity investment under an oligopolistic market structure in the liberalised energy market context is developed to capture the strategic behaviour of market participants. An annual investment model and an hourly operation simulation model are used to evaluate the value of hydrogen production, coupling components, and vector coupling storage in long-term investment decisions. The model, applied to the North of Tyne region in the UK, employs a scaled- down Future Energy Scenario dataset, reflecting a regional trajectory towards a net-zero emission target by 2050. Simulation results highlight market liberalisation's crucial role in attracting investments in renewable energy and hydrogen systems. Conversion efficiencies of electrolysers and fuel cells emerge as key profitability determinants, emphasising the significance of achieving at least 50% round trip efficiency for profitable vector coupling storage. The findings quantify the advantages of large-scale VCS investments over Li-ion battery storage.