Wave and tidal energy: part of the UK's energy mix

An explanation of the energy-producing potential of wave and tidal stream energy in the UK.


Wave and tidal stream energy is electricity generated from the movement of wave and tidal flows.

Wave power is much more predictable than wind power – and it increases during the winter, when electricity demand is at its highest. Tidal stream energy is also predictable and consistent.

It is estimated the UK has around 50% of Europe’s tidal energy resource, and a study in 2004 estimated the UK’s technical resource at around 16 terawatts per hour per year (TWh/year) (4% of overall supply).

Wave and tidal stream potential

Wave and tidal stream energy has the potential to meet up to 20% of the UK’s current electricity demand, representing a 30-to-50 gigawatt (GW) installed capacity.

Between 200 and 300 megawatts (MWs) of generation capacity may be able to be deployed by 2020, and at the higher end of the range, up to 27GWs by 2050 (see the Renewable Energy Roadmap).

The UK is currently seen as a world leader and focal point for the development of wave and tidal stream technologies because it has an abundance of marine energy resource.

With its excellent marine resource and its expertise in oil and gas exploration, the UK is in a unique position to benefit from this type of renewable energy – and to develop related wave and tidal stream services. The industry is still in its early stages however, and further research is needed to determine how best to exploit these assets.

Tidal range potential

Studies have estimated the UK’s total theoretical tidal range resource at between 25 and 30GWs – enough to supply around 12% of current UK electricity demand. The majority of this is in the Severn estuary (which has between 8 and 12GW), with the estuaries and bays of the north west representing a similar amount and the east coast a further 5 to 6GW.

The 2-year cross-government Severn tidal power feasibility study could not see a strategic case for public investment in a Severn tidal scheme in the immediate term, though private sector groups are continuing to investigate the potential. Other potential projects assessed by developers at sites around the UK include the Mersey, the Solway Firth and the North Wales coast.