The world first industrial-scale tidal power turbine, Simec Atlantis Energy’s 1.2MW SeaGen unit, has been decommissioned at its site in Strangford Lough, in Northern Ireland.

First installed in 2008 by then-owner Marine Current Turbines (MCT), the ‘surface piercing’ design, which featured twin 16-metre-diameter rotors that could be raised and lowered into the water on a central foundation column, produced 11.6GWh of power over its operating life.

Specialist UK marine contractor Keynvor MorLift handled engineering, planning and offshore works for the final phase of the decommissioning — which began in 2016 with the removal of the unit’s two 600kW powertrains — and carried out rigging, cutting and lifting of the 500-tonne support structure.

“SeaGen’s successful decommission represents a major milestone moment for the tidal power industry,” said SImec Atlantis’ CEO Tim Cornelius. “Not only has it validated the complete project lifecycle of a tidal stream energy development, moreover, we have done so with a tidal stream project of full commercial scale, that was connected to the grid.

“This [has been a] truly impressive feat of engineering.”

The SeaGen technology was an early poster-child for the global tidal power sector, being taken over by industrial giant Siemens in 2012 and further developed as a three-rotored device for installation at Canada's Force centre on the Bay of Fundy, before MCT was sold to Simec Atlantis in 2015.

A Simec Atlantis spokesperson told Recharge, the SeaGen's foundation structure is now en route to to a dry-dock in Swansea for where “all recyclable materials will be recycled – this is mainly steel – [and the] concrete sections will then be ground down as far as possible”.

Cornelius notes that the lessons learned from the SeaGen demonstrator “have underpinned both present and future global tidal turbine development while helping to shape the success of MeyGen”, the company’s multi-megawatt tidal stream array in Scotland’s Pentland Firth, which has to-date exported almost 20GWh of electricity to the UK national grid.