A two-stage planning and optimization model for water-hydrogen integrated energy system with isolated grid

To realize the vision of "carbon neutrality" in China, the use of clean energy and hydrogen energy storages can be integrated to optimize the structure of power systems and ensure safe, stable, and low-carbon operation of power. However, the current cost of hydrogen production is primarily associated to the high price of electricity, and the construction of an integrated energy system is a promising approach to solve this problem. In this study, a solitary grid energy system that integrates water and hydrogen has been developed, which consists of a hydroelectric power station, hydrogen production equipment, a hydrogen storage device, and a fuel cell. Furthermore, a two-layer programming model is designed. The upper layer is aimed at minimizing the construction cost to improve the hydrogen production capacity, hydrogen storage, fuel cell performance, and other facilities. Meanwhile, the lower layer is aimed at minimizing the decrease in daily operations to optimize the utilization of all the facilities in the integrated energy system under different scenarios. The Asynchronous Advantage Actor-Critic (A3C) reinforcement learning algorithm and Gurobi are used to solve the model. The results of typical scenarios show that the water-hydrogen integrated energy system saves water resources, maintains the stability of electric power, and provides improved economic benefits than those offered by single hydroelectric systems, thereby increasing the overall resource, social, and economic values of the system.