Tide and wave power is intermittent. How strong waves are depends on the strength of the wind, and the output of energy installations varies with the ebb and flow of the tides.
The sea is an almost inexhaustible energy source, and wave and tidal energy can offer a predictable and constant source of electricity. However, the technology to convert this energy into electricity is in early development and therefore expensive.
The UK has significant marine resources: a coastline of about 11,000 miles and some of the highest tidal ranges in the world. We lead the industry in developing technologies to convert marine energy into electricity on a large scale.
DECC estimates that wave and tidal energy has the potential to meet up to 20% of UK electricity demand (representing 30 to 50GW installed capacity).
Development of marine energy is in its early stages, but the UK already has a supply chain for manufacturing and constructing tidal turbines, and UK companies hold many relevant patents. Significant investment in research and development over many years will be required, however: to bring down costs and realise the potential of marine power as a large-scale contributor of electricity.