SeaGen was the world's first large scale commercial tidal stream generator. It was four times more powerful than any other tidal stream generator in the world at the time of installation. It was successfully decommissioned by SIMEC Atlantis Energy Limited in summer 2019, having exported 11.6GWh to the grid since 2008. The first SeaGen generator was installed in Strangford Narrows between Strangford and

Portaferry Portaferry () is a small town in County Down, Northern Ireland, at the southern end of the Ards Peninsula, near the Narrows at the entrance to Strangford Lough. It is home to the Exploris aquarium and is well known for the annual Gala Week Flo ...

Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...

. Strangford Lough was also the site of the first known

tide mill A tide mill is a water mill driven by tidal rise and fall. A dam with a sluice is created across a suitable tidal inlet, or a section of river estuary is made into a reservoir. As the tide comes in, it enters the mill pond through a one-way ga ...

in the world, the Nendrum Monastery mill where remains dating from 787 have been excavated.

History

Marine Current Turbines Marine Current Turbines Ltd (MCT), is a United Kingdom-based company which is developing tidal stream generators. It is owned by the German automation company, Siemens. History MCT was founded in 2000 to develop ideas of tidal power develop ...

, the developer of SeaGen, demonstrated first prototype of tidal stream generator in 1994 with a 15 kilowatt system in Loch Linnhe, off the west coast of

Scotland Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...

. In May 2003, the prototype for SeaGen, '', was installed off the coast of

Lynmouth Lynmouth is a village in Devon, England, on the northern edge of Exmoor. The village straddles the confluence of the West Lyn and East Lyn rivers, in a gorge below Lynton, which was the only place to expand to once Lynmouth became as bu ...

, North Devon, England. Seaflow was a single rotor turbine which generated 300 kW but was not connected to the grid. SeaFlow was the world's first offshore tidal generator, and remained the world's largest until SeaGen was installed. The first SeaGen generator was installed in Strangford Narrows between Strangford and

, in April 2008 and was connected to the grid in July 2008. It generated 1.2 MW for between 18 and 20 hours a day while the tides are forced in and out of

Strangford Lough Strangford Lough (from Old Norse ''Strangr Fjörðr'', meaning "strong sea-inlet"PlaceNames N ...

through the Narrows. During the commissioning of the system a software error caused the blades of one of the turbines to be damaged. This left the turbine operating at half power until autumn 2008. Full power operation was finally achieved on 18 December 2008. The system was removed in stages between 2016 and 2019, after Siemens sold the company and technology to rival Atlantis Resources (now

SIMEC Atlantis Energy SIMEC Atlantis Energy (formerly: Atlantis Resources) is a renewable energy company. It is incorporated in Singapore, but its operational headquarters are in Edinburgh, Scotland, United Kingdom. Initially, it was a developer of the tidal pow ...

) in 2015.

Technology

SeaGen generator weighed . It consists of twin axial-flow rotors, each driving a generator through a gearbox like a hydro-electric or wind turbine. These turbines have a patented feature by which the rotor blades can be pitched through 180 degrees allowing them to operate in both flow directions – on ebb and flood tides. The company claims a

capacity factor The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period. The theoretical maximum energy output of a given installation is def ...

of 0.59 (average of the last 2000 hours). The power units of each system are mounted on arm-like extensions either side of a tubular steel monopile some in diameter and the arms with the power units can be raised above the surface for safe and easy maintenance access. The SeaGen was built at Belfast's Harland and Wolff's shipyards.

Environmental impact

SeaGen has been licensed to operate over a period of 5 years, during which there will be a comprehensive environmental monitoring programme to determine the precise impact on the marine environment.

References

External links

Marine Current Turbines Ltd
{{Electricity generation in Ireland Tidal stream generators Tidal power stations in Northern Ireland Scottish inventions