Integrated Electricity and Hydrogen Energy Sharing in Coupled Energy Systems

Given that the capital cost of energy storage systems is still high, the concept of energy sharing attracts more attention. In this article, an energy sharing model in the forms of hydrogen and electricity is proposed. In this integrated sharing system, besides the aggregators who own power-to-gas (P2G) devices, plug-in hybrid electric and hydrogen vehicles (PH2EVs) aggregators become the new coupling points of the electricity network and gas network, because they can either consume electricity or hydrogen. In the objective function, the total social welfare considering energy dispatch in different systems is maximized. The distributed optimization method is applied to solve the formulated problem. In this way, the privacy of each aggregator can be protected. When the aggregator solves its sub-problem, it is not necessary to obtain all the system information. Besides, the computational complexity is reduced through the distributed optimization. Simulations are conducted on a 35-bus electricity network coupled with a 15-bus gas network. The simulation results reveal that the sharing amount of different kinds of energy can be obtained and the unified market clearing prices of each kind of energy can be achieved. It can be concluded that with the integrated energy sharing of hydrogen and electricity, the total system cost is the lowest and the largest total social welfare can be reached. Besides, the distributed energy storage can be more effective to improve the system stability.