An attractive feature of hydrogen is that it can also be used as a storage medium for electricity generated from intermittent, renewable resources such as solar, wind, wave and tidal power. It thereby provides a solution to one of the major issues of sustainable energy, namely the vexing problem of intermittency of supply. As long as hydrogen is produced from non-fossil-fuel feed stock, it is a genuinely sustainable or renewable fuel. Moreover, locally produced hydrogen allows the introduction of renewable energy to the transport sector, provides potentially large economic and energy security advantages and the benefits of an infrastructure based on distributed energy generation. It is this key element of the energy storage capacity of hydrogen that provides the potent link between sustainable energy technologies and a sustainable energy economy, generally placed under the umbrella term of ‘hydrogen economy