Baseload, Hydropower, Offshore, Project Development, Wind Power

Plans Submitted for 320-MW Swansea Bay Tidal Lagoon Project

Tidal Lagoon Power Ltd. has submitted an application for the first phase of its proposed 320-MW Swansea Bay Tidal Lagoon plant. The $1.2-billion tidal project will be set off the shores of Wales and is set to span six miles.

This proposal comes off the heels of the rejected $40-billion Severn Barrage tidal project back in September 2013.

Developers plan to start construction by 2015 and commission the project by 2018. If approved, Tidal Lagoon Power says that it will be the first of five separate lagoons planned to enter U.K. waters by 2023, which will likely supply 10 percent of the U.K.’s domestic electricity needs with more than 7,300 MW of capacity.

Swansea Bay would be the world’s first tidal project, and according to Mike Shorrock, chief executive officer of Tidal Lagoon Power, the more lagoons commissioned, the lower the project and energy costs. He predicts that tidal projects will eventually be able to compete with, and be cheaper than, offshore wind and eventually new nuclear plants. “Economies of scale bring immediate advantage…A second lagoon will require a lower level of support than offshore wind,” he said in a release.

Tidal lagoons are created by building a ring-shaped “sand-core breakwater or rock bund,” which resembles a harbor wall, typically constructed from mainly sand and rock. Turbines mounted in concrete casing are submerged and lined within the wall. When the tide moves in and out, the wall holds water back, and once it reaches a certain level, gates are opened and the water flows through the turbines, which creates electricity.

Though the project is still waiting on the environmental go-ahead, experts state that tidal lagoon projects have much less environmental considerations than the heavily criticized Severn Barrage proposal. The 11-mile barrage would have spanned the length of the bay. Barrages allow high tide to flow in, but hold water back until the opportune moment to capture energy as the water recedes. Tidal lagoons take up 40 percent less space than a barrage and allows water currents to flow around the project.

“This technology will have less impact on fish and other wildlife than the barrage proposals, which conservationists have spent several years fighting in the estuary, and which the government has repeatedly rejected,” Sean Christian, special sites spokesman for the bird and wildlife lobby RSPB told The Guardian. “However, it could still have major impacts on the estuary and its wildlife, and we will need to look at the details of each lagoon proposal closely.”