Off-Grid Green Hydrogen Production Systems

This chapter introduces the role of hydrogen in the current energy system transition: from fossil-based to renewable and low-carbon emission sources. Although solar and wind energy are abundant renewable sources, the intermittence of electricity generation remains a challenge for security of supply and causes instabilities in the electricity grid. The integration of green hydrogen produced by water electrolysis into a smart energy system –or a smart grid–, is considered a promising solution to overcome the handicaps of the renewable electricity production and certain hard-to-decarbonize industrial sectors. The principle of water electrolysis along with the different electrolyzer technologies is also presented in the first section. In the second section, a numerical model of an industrial alkaline water electrolyzer plant is described. The different unit operators that comprise the system to produce purified hydrogen are individually introduced. The chapter concludes by showing the capabilities of an off-grid water electrolyzer system, which consists of a battery energy system and solar PV and wind power installations. Simulation of the plant demonstrates, as a proof of concept, the feasibility of the system for future integration into a smart energy system.