West Somerset Lagoon
Location: West Somerset
Client: West Somerset Lagoon LTD
Sector: Infrastructure
Team
Architect: Marks Barfield Architects
Hydro-Environmental Modelling Research: Cardiff University
Designated Consultants: Mott Macdonald
Industry Body: BHA
Legal Support & Advice: Burges Salmon
Economics Regulation Advice: Oxera
Strategic Risk Advice: Oxford Global Projects
Independent Fisheries Adviser: Fishtek Consulting
Advice on Fish Mitigation: Fish Guidance Systems
The West Somerset Tidal Lagoon is a proposed Tidal Range power scheme, that aims to harness the energy of the tides to provide reliable, predicatable, renewable energy. It is strategically located on the southern coast of the Bristol Channel Basin between Minehead and Watchet to take advantage of the world’s second highest tidal range and currently completely untapped.
The West Somerset Tidal Lagoon would harness the energy of the tides powered, by the moon, to provide the UK with long life, cost effective, clean, proven, predictable, renewable energy, and could become one of the UK’s largest renewable energy projects.
The lagoon will deliver renewable
energy for 2m UK ‘median usage’
homes (Ofgem)
Untapped energy source
The Bristol Channel Basin has the 2nd highest tidal range in the world.
Long life 120+ year life span
4x wind+solar
2x nuclear
Reliable energy
Generates energy on both ebb and flood tides. Could provide continuous energy with short term storage
Affordable
Cost per MWh with Regulated Asset Base funding is similar or cheaper than nuclear
Predictable energy
Unlike the sun and wind, the tides are reliable and predictable well into the future
Cost £10.5bn
(Estimated at 2023 prices)
Delivery
5yrs to start generation. Simple repeatable construction method.
Why West Somerset?
The West Somerset Lagoon has been strategically located on the southern coast of the Bristol Channel Basin between Minehead and Watchet to take advantage of the world’s second highest tidal range. At Minehead the tidal range will be up to 10.9m, generating the maximum energy possible whilst minimising environmental, economic and visual disturbance. The proposed lagoon will be located:
• outside of navigation channel to Bristol and Cardiff Ports
• outside of Special Areas of Conservation (SAC), Special Protection Areas (SPA) and Local Nature Reserves (LNR).
• where no major rivers are enclosed
• where it provides coastal protection against storms and sea level rise
Social and Environmental Benefits
The area of West Somerset currently experiences social and economic deprivation and has been identified by the UK Government as the least socially mobile area in the country.
This project will add significant social, environmental and economic benefits to local communities, and wider regional communities in the Southwest England and South Wales, for generations to come.
It will have a transformational impact on Minehead and the region, enriching cultural
and leisure opportunities, as well as the quality of the public realm whilst also creating well paid, year round, skilled jobs.
How does it work?
The 14 km semi-circular lagoon wall, which will impound about 80 km2 of water, maximises the lagoon area whilst minimising the wall perimeter length, resulting in minimum unit energy cost. The lagoon wall will contain 125 turbines that will generate power on the ebb and flood tides along with an array of sluice gates to maximise power generation, maximise water quality and minimise silt deposition. A ship lock is included near the Minehead landfall, sized to suit construction and maintenance vessels.
The scheme would generate 6,500GWh/y of renewable energy, utilising bi-directional turbines operating in both ebb and flood generation modes, which maximises the hours of generation per day.
This is proven technology similar to La Rance in Brittany and Sihwa Lake in South Korea. The 58-year-old La Rance scheme should continue for another 50 + yrs. Sihwa
Lake Tidal Power Plant.
