Green Building and Energy Management

1.2 MW plant installed off the coast of Northern Ireland
A new type of renewable energy has been connected to the European grid: tidal energy turbines. The SeaGen Tidal System has been installed in the Strangford Narrows, about 400 metres off the coast of Northern Ireland, by Marine Current Turbines Ltd (MCT). The installation was completed last April and the generators were successfully connected to the grid on 17th July. It produces 1.2 MW of power, operating 18 to 20 hours a day. The total manufacturing and installation cost was nearly £10 million.
Like a wind turbine, but more predictable
The Seagen Tidal System consists of a fixed structure bearing two 16m diameter axial flow rotors, each connected to a generator via a gearbox. In contrast with other existing tidal power plants — such as the one on the Rance in France — this system does not require a barrage closing in an estuary. It is sited offshore on a large piling.
The technology is similar in many respects to a wind turbine. However, its principle advantage compared to most other renewable sources is that tidal energy is entirely predictable. In addition, its visual impact is much smaller since it is almost entirely submerged. The slow rotation speed (10 to 15 revolutions per minute) is unlikely to pose a threat to either fish or marine mammals.