摘要
Large areas in many countries are populated but have no connection to a national electricity grid. Centralised electricity generating facilities burning fossil fuels have been the norm. Renewable energy resources, especially solar/wind energy, are now penetrating this sector. Long-term energy storage is the universal challenge in providing renewables-based electricity with high availability across the seasons. Here we review and discuss the use of hydrogen as the energy vector by means of which solar/wind energy is transformed, stored and made available as electricity. The dominant system configuration is presently photovoltaic electricity used to electrolyse water to produce hydrogen, which is stored as a pressurised gas or metal-hydride, then retrieved from storage to generate electricity in a fuel cell. We survey the demonstration projects reported in the literature and discuss the need for authoritative system modelling in order to size the system components for minimum cost at a designated availability of supply.