Dynamic minimum loads for FCR market participation of alkaline water electrolyzers

The provision of frequency-supporting ancillary services to the grid can strengthen the economic outlook of renewable hydrogen production. The optimal power dispatch problems for electrolyzer plants providing frequency containment reserve (FCR) services usually consider the electrolyzers' minimum load as a static constraint both for hydrogen production and the provision of frequency reserves. In this paper, we propose the use of a less conservative constraint, in which a dynamic minimum load is defined such that it does not violate process safety constraints during the activation of FCR. We present a case study for which the proposed limit is inferred using a comprehensive dynamic model of the electrolysis plant. We further show that using this dynamic minimum load in the optimal scheduling problem can lead to significant reductions in the operating cost of the plant.