The UK sits at the heart of one of the world's greatest tidal energy resources. Perfectly predictable, utterly renewable — tidal stream, tidal range and wave energy could power millions of UK homes. The technology is finally arriving.
Unlike wind and solar, tidal energy is completely predictable centuries in advance. The tides are driven by the moon and sun — forces no weather event can disrupt. This predictability makes tidal power uniquely valuable for grid planning. It doesn't need storage or backup — it just needs to be harnessed at the right locations. The UK has more of those locations than almost anywhere on Earth.
Underwater turbines placed in fast-flowing tidal channels — like wind turbines but beneath the sea surface. The UK's strongest tidal streams are in the Pentland Firth, Orkney and the Channel Islands.
The UK has some of the world's largest tidal ranges. The Severn Estuary (14m tidal range) could generate ~5% of UK electricity from a barrage — but environmental concerns have stalled every proposal. Tidal lagoons offer a potentially less impactful alternative.
Wave energy is technically more difficult than tidal stream but the resource is enormous. The UK Atlantic coast has some of Europe's best wave energy conditions. Multiple technologies are being tested.
Wave energy has proved more technically challenging than predicted. The harsh ocean environment damages devices faster than the energy they produce can justify at current scale. However, applications for remote power (oil rigs, subsea monitoring, aquaculture) are commercially viable at smaller scale — this is the current commercialisation path. UK's ORE Catapult supports wave device testing and scale-up.
Orkney is the world's capital of marine energy. The European Marine Energy Centre (EMEC) has hosted more wave and tidal devices than any other site on the planet.
Founded 2003, based in Stromness, Orkney. Grid-connected wave test site at Billia Croo; tidal test site at Fall of Warness (Eday). 19 wave devices and 17 tidal devices have been tested to date.
Surplus tidal generation during off-peak periods can be used to make green hydrogen via electrolysis. In Orkney, community wind turbines already produce green hydrogen. Tidal stream's predictable generation profile makes it well-suited as a hydrogen feedstock alongside variable renewables.
Tidal is one piece of the UK's immense renewable resource. Discover wind, solar, storage and hydro.