Hydrogen and fuel cells

Considering social (e.g. energy security), economic, and environmental issues associated with reliance on finite fossil fuel resources for energy generation, hydrogen (based on renewable energy and energy efficiency) is seen by many scientists and economists as a sustainable solution that can help the end users of energy meet their future supply requirements as well as greenhouse gas and other emission reduction targets. While diversity of renewable energy resources is the key advantage of these alternatives, their intermittency and unpredictability have to be addressed by complementing them with proper energy storage options such that these resources can be reliably employed to power stationary and mobile applications uninterruptedly as required. Hydrogen energy systems as reviewed in this chapter can play a strong energy storage role in conjunction with renewable energy resources, particularly in applications with long-term (e.g. in stand-alone stationary applications with highly variable seasonal input of renewables, central grids, or microgrids) and/or long-range (i.e. in automotive applications) energy storage requirements. The main components of a hydrogen energy system include hydrogen generation arrangement; hydrogen storage; distribution and delivery systems (long or short distance); and the means of converting the chemical energy of hydrogen into a desirable form of energy (e.g. electricity) for end consumers. Latest research and development related to these elements are discussed in this chapter.