Hydrogen storage - status and prospects

More than three decades of research have not solved the problem of storing hydrogen on board for transport fuel. Hydrogen storage therefore constitutes a major technological barrier to the hydrogen economy. The present paper considers why the problem is so tough and assesses the prospects for the two most popular storage concepts, pressurised gas storage systems and condensed materials, exemplified by lithium based complexes. It is concluded that efforts to achieve 'condensed matter' hydrogen storage are showing promise and are still vitally important because pressurised gas storage for automobiles is very unlikely to meet the targets for energy density set by the US Department of Energy.