Optimal sizing and energy management of an integrated energy system coupling a hydrogen-fueled gas turbine with storage for Power-to-Power and hydrogen supply

In this work, an integrated energy system combining a wind plant, a solar plant, an electrolyzer, a compressor, a salt cavern as storage, and a fully-hydrogen-powered gas turbine plant is assessed for net-zero demand load matching based on the Power-to-Hydrogen-to-Power process. A bi-level optimization framework is proposed with an outer layer using a genetic algorithm to find the optimal installed capacities of renewables, electrolysis, storage and turbine plant, to maximize the net present value of the project, and an inner linear programming layer formulated as a cost minimization unit commitment problem for the energy management strategy. The Australian context is chosen to conduct a reliability, techno-economic and environmental performance analysis. Results highlight that demand is met as renewables supply base power, hydrogen turbine completes balance, electrolyzer converts excess renewables, and storage acts as buffer. Selling hydrogen to a refinery brings in additional revenues, but subsidies or other revenues streams such as ancillary services are necessary to reach profitability.