Great Western Power Barrage

The UK government has committed to an ambitious plan to de-carbonise the economy, from the phasing out of gas generated power stations to expanding the use of electric vehicles.

The tide is so reliable that tide height tables can be published years in advance. This steady and reliable power source stands in contrast to the intermittency of wind and solar power, where even the next week is uncertain.

Unique geographical features give the Severn Estuary a tidal range up to 15m, the second largest in the world. A barrage in this area could provide a colossal 8-15 GW. This is equivalent to 500-1000 of the world’s largest wind turbines and it will be at least twice as big as any other UK power plant.

There are multiple ways to harness the power of the Severn Estuary - including tidal stream turbines, lagoons or a barrage. We believe that a tidal barrage is by far the most effective and environmentally friendly solution for unlocking the potential of the estuary.

Any major investment requires certainty; the Great Western Power Barrage is based on totally proven technology. The La Rance Tidal Barrage in Brittany, France (1963) and the Sihwa Tidal Barrage Power Plant in South Korea (1997) are examples of successfully harnessing tidal energy.

The primary expected environmental effect of the barrage will be a small reduction in the tidal range and velocity. This is expected to produce ecological benefits including the re-establishment of salt marshes and the enhancing of the food chain in the estuarine waters.

There will be a significant reduction in flooding risk and coastal erosion.

The carbon payback period is expected to be less than 24 months.

The barrage will provide a boon to local employment and will enhance the region’s stability by significantly reducing flooding risk and coastal erosion. It will also contribute to the UK’s energy reliability and independence.

The reduced flow velocities in the channel will encourage more leisure activity.

Upstream ports will remain accessible by a simple lock system.

The history dates back to Thomas Fulljames’ initiative in 1849. Since that time there have been a number of proposals for a barrage across the estuary including ones investigated by the UK Government. The time was never ‘right’ - up until now.