Midilli, AAy, MDincer, IRosen, MA2019-08-012019-08-0120051364-0321https://dx.doi.org/10.1016/j.rser.2004.05.003https://hdl.handle.net/11480/5593This article deals with hydrogen energy as a clean energy carrier, discusses the key role of hydrogen energy technologies and systems, and compares hydrogen with other energy forms. Energy strategies that incorporate hydrogen are considered, and the importance of hydrogen energy in achieving a sustainable energy system is discussed. Exergetic, environmental, sustainability and other perspectives are considered. (C) 2004 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/closedAccessenergyexergyhydrogenrenewable energysustainabilityReview Article9325527110.1016/j.rser.2004.05.0032-s2.0-8444221653Q1WOS:000226423500002Q1