Celebi, C.Altınışık, H.Atak, Y.N.Çolpan, C.Devrim, Y.2026-03-052026-03-0520259780443132193978044334108310.1016/B978-0-44-313219-3.00048-42-s2.0-105029496621https://doi.org/10.1016/B978-0-44-313219-3.00048-4https://hdl.handle.net/20.500.14411/11205Electrolyzers are at the forefront of sustainable energy technologies, which are important in converting electrical energy into storable and transportable chemical energy. Electrolyzers enable the production of environmentally friendly green hydrogen using excess electricity from renewable sources, thereby reducing outage problems and facilitating grid balancing. Furthermore, using hydrogen as an energy carrier has great potential for decarbonizing hard-to-decarbonize sectors such as heavy industry, aviation and shipping. This chapter provides a comprehensive overview of electrolyzers, covering their basic principles, their various types and their significant importance in the transition to a greener energy environment. The chapter first discusses the basic operation of electrolyzers and explains the electrochemical processes involved in decomposing water molecules into hydrogen and oxygen gases. Each type of electrolyzer is discussed in detail, highlighting their unique features, efficiency, scalability, and technological advancements. Comparative analysis between electrolyzer types provides insights into their suitability for various applications and deployment scenarios. In conclusion, this chapter highlights the critical role of electrolyzers in enabling the hydrogen economy and advocates for continued research, development and deployment efforts to harness their full potential in moving towards a sustainable and carbon-neutral future. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.eninfo:eu-repo/semantics/closedAccessAlkaline ElectrolyzerAnion Exchange Membrane ElectrolyzerDecarbonizationElectrolysisElectrolyzerGreen HydrogenPEM ElectrolyzerPerformance of ElectrolyzerSolid Oxide ElectrolyzerThermodynamicsBook Part