Chapter 2. Alkaline Electrolysers

Abstract

Alkaline electrolysers provide a simple, cheap and efficient electrochemical route to hydrogen production. Coupled with renewable electricity generation sources it has the potential to provide large scale, long term energy storage, grid balancing and enhanced energy transport. Recent advances in electrode materials, cell design and membrane performance have increased the cost effectiveness of the technology towards a level where the industry for alkaline electrolysers is booming; indeed units of above 1 MW are already being used in the field, and the sector looks set for more increases in capacity and system sizes in the near future. This chapter introduces the theory that underpins alkaline electrolysis, including the underlying thermodynamics and electrode kinetics that govern the process. The individual components that make up the cell are introduced and the current state of research of each part is investigated to provide a comprehensive discussion of the full system. The overall status of the technology is reviewed, with the performance of commercial systems compared and the future prospects of the technology are discussed.