Plans have been released for the world’s first, purpose-built, tidal lagoon power plant that will be capable of generating electricity equivalent to the entire domestic consumption of Swansea in South Wales.
The proposed 250MW power plant will produce predictable, base load electricity for 16 hours each day, using both the ebb and flood tides. It will save over 200,000 tonnes of CO2 per year for its design life of over 100 years. The project represents an investment of £650m and according to the development company behind the scheme is a significant opportunity for Wales to take the lead in the tidal industry for the UK. The power plant could be connected to the National Grid and be ‘power ready’ in 2017.
The tidal lagoon will comprise a ‘land attached’ impoundment, located between the dredged channels of the Tawe and Neath rivers. The impounded area will be surrounded by a 10km long wall. Landfall points will be located at or near Swansea Docks, but the lagoon will not obstruct the entrance to any rivers or marinas, nor adversely affect the operation of the port.
The total height of the seawall will be approximately 11m (shore side) and 19m (offshore). The visibility of the wall at low water will be 11.3m, at high water it will measure 2.8m. The site will have a total installed capacity of circa 250MW with a potential annual output of circa 400GWh.
Tidal Lagoon Power plc, the company behind the project, says it will hopefully be the first in a network of lagoons around the UK. Electricity is generated by creating a ‘head’ of water, a difference in water level between the inside and outside of the lagoon, and channelling the resulting flow through turbines. Once there is a sufficient difference in water level, the lagoon gates are opened and the turbines begin to generate. It is proposed to generate on both the incoming (flood) tides and outgoing (ebb) tides, maximising the energy extraction potential from any site.