Tidal power powered SeaGen, the world’s first commercial tidal-stream turbine project installed in Northern Ireland in 2008.
SeaGen was installed in Strangford Lough, County Down, by Marine Current Turbines. Its twin underwater rotors were driven by fast tidal currents, turning generators to produce electricity. The project entered full operation in 2008 and demonstrated grid-connected generation from moving seawater.
Tidal-stream systems differ from tidal barrages. A barrage uses a dam-like structure across an estuary and exploits water-level differences, while tidal-stream turbines operate in flowing water without enclosing the whole basin. SeaGen was therefore a landmark for underwater current technology rather than conventional tidal impoundment.
Tidal energy is highly predictable because tides follow astronomical cycles. It remains less widely deployed than wind and solar because underwater construction, maintenance, corrosion, marine ecology, and high costs create difficult engineering and financial challenges.