Transmission Expansion Planning With Feasible Region of Hydrogen Production From Water Electrolysis

Hydrogen production has been advocated as a promising way for the decarbonization of power systems based on renewables. By using the renewable curtailments to produce the hydrogen gas that will be used for power supply when necessary, water electrolysis can work with transmission expansion planning (TEP) to improve renewable utilization. In this article, it is found that the nonlinear electrochemical characteristics of water electrolysis can be equivalently formulated as the feasible region that consists of two convex subregions, in the space of consumed renewable power and produced hydrogen gas. Regarding this finding and the typical application scenario where hydrogen gas is stored in gasholders and then used in hydrogen oxygen fuel cells, TEP with water electrolysis is further established as a mixed-integer nonlinear programming problem. In our formulation, two linear relaxation technologies are presented to handle both the complementary constraints of the gasholders and the selection of which subregion of water electrolysis. Numerical results in the Garver 6-bus test system and a 661-bus utility system demonstrate the effectiveness of the presented methods.