Expanding flexibility with P2H for integrated energy systems

Combined heat and power (CHP) unit serves as a significant kind of heating source in energy systems, but its heat production must be accompanied by electric production. It could worsen the wind power curtailment in the context of large-scale installed wind farms, which is unfriendly to the integrated energy system operation. Power to hydrogen (P2H), a promising energy conversion technology, is a possible solution to mitigate this issue by consuming excessive electric power, and stored hydrogen can be used in many fields, such as fuel cell and chemical synthesis. Hence, this paper designs an integrated energy system optimisation model with P2H to discuss the feasibility of combining electric power, heat and hydrogen together. Water electrolysis is modelled with an electricity-hydrogen conversion efficiency factor, which is easy to be integrated into a mixed integer optimization problem that mimics the system operation in a 24-hour period. Three cases are designed to demonstrate that the application of P2H improves operating flexibility, and more specifically, the flexibility is visualized by showing equivalent operating region of CHP units.