The realisation of the hydrogen economy has been the HolyGrail of energy research in the 21st century (Rifkin, 2002). The generation of hydrogen from wind or photovoltaic-poweredelectrolysis will provide a way to buffer the variations in thesecarbon-free energy sources and produce a clean fuel fortransportation. The infrastructure will be developed centrally tobegin with and may then be deployed in a dispersed fashion ascosts are driven down. The initial deployment needs a gridcapable of pooling both energy demand and supply. In the longerterm, this infrastructure may no longer be needed as smaller-scaleequipment becomes viable. But, as with any emerging technology,realising economies of scale and maximising efficiency and theuse of existing infrastructure will be preconditions for commercialsuccess.The outlook for commercial success in 2050 and beyonddepends on the resolution of many technical problems. Theseinclude serious safety and technical concerns with the storage andtransportation of hydrogen.