Hydrogen is an ‘energy carrier’ rather than a fuel source as, like electricity, it can only be produced using energy.
Hydrogen can be used in:
a fuel cell, where it produces zero emissions at the point of use
normal combustion, (eg in an internal combustion engine).
In 2004, the Department of Trade and Industry, commissioned analysis from the energy consultants E4Tech, Element Energy, and Eoin Lees. This analysis indicates that for the UK, the use of hydrogen as a transport fuel offers significant opportunities for cost-competitive carbon dioxide reduction by 2030. Six different types of transport energy chain have this potential and also offer increased energy security. None is readily available today and each would require significant changes to the energy system. However, they are sufficiently promising to be worth pursuing as energy options for the UK. This analysis was published on the Department’s website and can be found at: http://www.dti.gov.uk/energy/sources/sustainable/hydrogen/page26734.html.