- Project name: SeaGen S tidal turbine (1.2 MW)
- Technology: Tidal stream energy converter
- Developer: Marine Current Turbines Ltd (MCT)
- Location deployed: Strangford Lough, Northern Ireland, United Kingdom
- Commissioned: 2008
- Decommissioned: 2019
- Rated capacity: 1.2 MW (two × 600 kW turbines)
Developer: Marine Current Turbines Ltd (MCT)
Marine Current Turbines Ltd (MCT) was a UK-based renewable energy company founded in 2000 and headquartered in Bristol, England. Its core business was designing and developing tidal stream generators — underwater turbines that capture kinetic energy from tidal flows and convert it into electricity. MCT created the SeaGen family of devices, including the 1.2 MW SeaGen S system, which became the first commercial-scale tidal turbine connected to a national grid.
Ownership history:
Siemens acquired a majority share in MCT in 2012 and later full ownership before selling the business to Atlantis Resources (now SIMEC Atlantis Energy Ltd) in 2015.
Founder and key figure:
The SeaGen technology was developed under the leadership of Scottish marine engineer Peter Fraenkel, who invented the SeaGen tidal power system and guided its technical design.
SeaGen S 1.2 MW tidal turbine — technology summary
SeaGen S was a twin-rotor tidal turbine system designed to harness the predictable ebb and flow of tidal currents in coastal waters. The device operated much like an underwater wind turbine, with large rotors driven by water flow rather than wind.
Key features:
- Twin turbines: Two 600 kW axial-flow rotors mounted on a single support structure.
- Bi-directional operation: Rotor blades could pitch through 180 degrees to generate on both incoming and outgoing tides.
- Maintenance design: The turbines were mounted on a cross-beam that could be raised above the water for routine servicing.
- Rotor size: Each rotor had a diameter of approximately 16 m.
Performance and impact:
- SeaGen S was the world’s first commercial-scale tidal stream generator and supplied electricity into the UK grid from 2008 to 2019.
- During its lifetime, it generated over 11.6 GWh of clean energy.
- It demonstrated tidal stream power as a feasible renewable technology, supporting later marine energy research and deployment globally.
Decommissioning:
The SeaGen S system was officially decommissioned by SIMEC Atlantis Energy Ltd in 2019, completing the life cycle of the project and providing valuable data for future tidal developments.
Sector significance
SeaGen S is recognised internationally as a pioneering commercial tidal energy installation, marking a major step in marine renewables by proving that tidal stream turbines can operate reliably at multi-megawatt scale and contribute to national electricity supplies. Its success helped shape understanding of design, environmental interaction and long-term operations for tidal devices.