Coordinating system operators to optimise integrated energy system operation

Energy systems must keep pace with the changing energy landscape, and thus the processes to operate and analyse energy systems must evolve. Integrating electricity and natural gas systems presents a significant opportunity to enhance system flexibility. However, the specialisation of energy system operators necessitates an overhaul of system operator hierarchy to facilitate system integration. This paper presents a novel solution method framework to explore the optimal coordination hierarchy of energy system operators with varying levels of information sharing. Three scenarios are examined. In the first, individual optimal power and gas flow problems are solved, representing the minimisation of energy dispatch costs by two independent, decentralised operators. In the second, these individual optimisation problems are merged into a single optimal energy flow problem, representing the centralised co-optimisation of electricity and gas dispatch. The third scenario introduces secure, two-way information sharing between two decentralised operators, achieved through a novel application of Benders’ decomposition to the non-convex optimal energy flow problem. These methods are applied to a standard test system for integrated electricity and natural gas systems. Results show that centralised coordination yields the lowest cost mix of energy producers, in the most efficient time. Additionally, system operator hierarchy strongly influences the dispatch profiles of electricity generators and affects the performance of incremental gas flow linearisation. Benders’ cuts converge to a local optimum, marginally increasing information sharing and network efficacy in the non-convex environment. Ultimately, these findings underscore the value of centralised coordination in the future operation of integrated energy systems. • A single system operator provides the lowest cost energy supply mixes. • A single system operator improves computational optimisation efficiency. • System operator hierarchy impacts dispatchable generation and gas flow. • Benders’ decomposition marginally increases information share among operators. • In a non-convex IEGS, Benders’ cuts may converge to a local optimum.