Coupling time varying power sources to production of green-hydrogen: A superstructure based approach for technology selection and optimal design

Abstract

Green hydrogen is a promising alternative for decarbonization of the economy. Its production is based on electrolysis powered by energy from renewable sources. Modern renewable sources like wind or solar are of an intermittent nature, a fact that poses a challenge to the operation of the electrolyzers. In this work, we present a superstructure-based optimization framework to design hydrogen production processes. The design involves selection of the power sources (wind/sun generators, grid), selection of the type and size of electrolyzer, and selection of energy storage devices (battery, vessels). The case studies include hydrogen production at different scales to allow a discussion on patterns of technology selection strategies and the synergies between them. Overall, our simulations show that solid oxide electrolyzers are a promising option, and that from the currently market available alternatives, alkaline electrolysis is preferred over proton exchange membrane electrolysis. Our results support the idea that complementary of the pattern of the energy sources should be sought, but not the idea of producing hydrogen to take advantage of energy surplus and avoid curtailment.