Hydrogen and fuel cells are related but distinct technologies which offer the potential for low and ultimately zero CO2 emissions and increased energy security.
Hydrogen is an energy carrier (like electricity) which requires a source of primary energy to make it. Hydrogen can be produced from a number of different sources including fossil fuels such as coal or natural gas, renewable energy sources such as wind, hydro and biomass, or nuclear. Hydrogen can be converted to electricity and heat using modified internal combustion engines, gas turbines or fuel cells.
Fuel cells convert hydrogen (or a hydrogen-rich gas stream) into electricity and heat by an electrochemical process which results in water (or steam) being the only emission. The technology has applications for stationary power generation and combined heat and power (CHP) – distributed generation or microgeneration, portable power, and transport (as a replacement for the internal combustion engine).
These technologies are currently being demonstrated, but they will have to overcome significant techno-economic barriers in order to displace the incumbent technologies. The timing of commercialisation will depend on the application. Niche applications such as portable and remote power are expected to be first, followed by stationary power/CHP, and finally transport.