It is important to stress that, unlike coal, gas or oil, hydrogen is not a primary energy source. Its role more closely mirrors that of electricity as an ‘energy carrier’, which is produced using energy from another source and then transported for future use, where its stored chemical energy can be utilised. Hydrogen can be stored as a fuel and utilised in transportation and distributed heat and power generation using fuel cells, internal combustion engines or turbines, and, importantly, a hydrogen fuel cell provides only water and no CO2 at the point of use