View source for SeaGen

{{Short description|Large-scale tidal stream generator (2008–2019)}}
{{use dmy dates|date=January 2021}}
{{About|the first large scale commercial tidal stream generator|the American biotechnology company|Seagen}}{{Infobox power station
| name = SeaGen
| name_official = 
| image = SeaGen installed.jpg
| image_size = 
| image_caption = Commercial tidal stream generator — SeaGen — in [[Strangford Lough]]. The visible wake is indicative of the power of the tidal current.
| image_alt = 
| location_map_size = 
| location_map_caption = Location of SeaGen in Northern Ireland
| location_map_alt = 
| coordinates = {{coord|54|22|7.2|N|5|32|45.8|W|region:GB_type:landmark|display=inline,title}}
| coordinates_ref = 
| country = [[Northern Ireland]], United Kingdom
| location = Strangford Narrows between [[Strangford]] and [[Portaferry]]
| status = Decommissioned
| construction_began = 
| commissioned = April 2008
| decommissioned = July 25 2019
| cost = 
| owner = SIMEC Atlantis Energy Limited
| operator = 
| tide_technology = 
| tide_tsg_type = 
| tide_barrage_height = 
| tide_barrage_length = 
| tide_barrage_width = 
| tide_crosses = 
| tide_channel_width = 
| tide_channel_speed = 
| tide_dtp_length_perp = 
| tide_dtp_length_para = 
| tide_range = 
| ps_units_operational = 
| ps_units_manu_model = 
| ps_units_uc = 
| ps_units_planned = 
| ps_units_cancelled = 
| ps_units_decommissioned = 2 x 0.6 MW
| ps_electrical_capacity = 1.2 MW
| ps_electrical_cap_fac = 
| ps_annual_generation = 
| website = 
| extra = 
}}
'''SeaGen''' was the world's first large scale commercial [[Tidal stream generator|tidal stream]] [[Electrical generator|generator]].<ref name=engineering>{{Cite journal 
 | last1 = Douglas | first1 = C.A.
 | last2 = Harrison | first2 = G.P.
 | last3 = Chick | first3 = J.P.
 | title = Life cycle assessment of the Seagen marine current turbine 
 | url=https://commerce.metapress.com/content/l2525g3001286200/resource-secured/?target=fulltext.pdf&sid=vwpwqjm0htfuvn45hmy4wf45&sh=journals.pepublishing.com
 | format = PDF 
 | year= 2008
 | accessdate = 2008-07-10
 | doi = 10.1243/14750902JEME94
 | journal = Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment
 | volume = 222
 | issue = 1
 | pages = 1–12
 | publisher= Professional Engineering Publishing| bibcode = 2008PIMEM.222....1D
 | s2cid = 111126521
 | hdl = 20.500.11820/935cdfa5-aeed-423c-aa52-f51c5e5753ef
 | hdl-access = free
 }}
</ref><ref name=independent>
{{cite news
 | url=https://www.independent.co.uk/environment/green-living/the-rise-of-british-sea-power-799630.html
 | archive-url=https://web.archive.org/web/20080327091844/http://www.independent.co.uk/environment/green-living/the-rise-of-british-sea-power-799630.html
 | url-status=dead
 | archive-date=27 March 2008
 | title=The rise of British sea power
 | newspaper= [[The Independent]]
 | date=2008-03-23
 | accessdate=2008-07-30}}
</ref><ref name=channel4>
{{cite news
 | url= http://www.channel4.com/news/articles/science_technology/power+generation+the+new+wave/1907547
 | title= Power generation: the new wave
 | author= Julian Rush
 | publisher= Channel 4
 | date=2008-03-31
 | accessdate=2008-07-30}}
</ref> It was four times more powerful than any other tidal stream generator in the world at the time of installation.<ref name=bbc>
{{cite news
 | url=http://news.bbc.co.uk/1/hi/northern_ireland/7233829.stm
 | title=Sea change for energy generation
 | author=Arthur Strain
 | publisher=[[BBC]]
 | date=2008-02-08
 | accessdate=2008-07-10}}
</ref> It was decommissioned by SIMEC Atlantis Energy Limited in summer 2019, having exported 11.6&nbsp;[[GWh]] to the grid since 2008.<ref name=":0">{{Cite web |date=2019-07-26 |title=Atlantis Successfully Decommissions 1.2 MW SeaGen Tidal System in Industry First |url=https://simecatlantis.com/2019/07/26/meygen-operational-update-3-2/ |archive-url=https://web.archive.org/web/20190903161227/https://simecatlantis.com/2019/07/26/meygen-operational-update-3-2/ |archive-date=2019-09-03 |access-date=2019-09-03 |website=SIMEC Atlantis Energy |language=en-GB}}</ref> 

The first SeaGen generator was installed in Strangford Narrows between [[Strangford]] and [[Portaferry]] in [[Northern Ireland]]. Strangford Lough was also the site of the first known [[tide mill]] in the world, the [[Nendrum Monastery mill]] where remains dating from 787 [[common era|CE]] have been excavated.

==History==
[[Image:Seagenraised.jpg|left|thumb|The SeaGen rotors could be raised above the surface for maintenance.]]
[[Marine Current Turbines]], the developer of SeaGen, demonstrated its first prototype of a tidal stream generator in 1994 with a 15&nbsp;kilowatt system in [[Loch Linnhe]], off the west coast of [[Scotland]]. In May 2003, the prototype for SeaGen, '{{visible anchor|SeaFlow}}', was installed off the coast of [[Lynmouth]], [[North Devon]], England.<ref name=technology/> Seaflow was a single rotor turbine which generated 300&nbsp;kW but was not connected to the grid. SeaFlow was the world's first offshore tidal generator, and no larger turbines were installed until SeaGen.<ref name="berr">
{{cite web |title=Case Studies for Schools: Tidal Power |url=http://www.berr.gov.uk/energy/sources/renewables/schools/case-studies/tidal/page23016.html |archive-url=https://webarchive.nationalarchives.gov.uk/ukgwa/20090609054344/http://www.berr.gov.uk/energy/sources/renewables/schools/case-studies/tidal/page23016.html |archive-date=2009-06-09 |accessdate=2008-07-10 |publisher=Department for Business, Enterprise and Regulatory Reform}}
</ref>

The first (and only) SeaGen generator was installed in Strangford Narrows between [[Strangford]] and [[Portaferry]] in [[Northern Ireland]], in April 2008 and was connected to the grid in July 2008.<ref>{{Cite web |date=17 July 2008 |title=World's first commercial-scale tidal power system feeds electricity to the National Grid |url=http://www.marineturbines.com/3/news/article/10/world_s_first_commercial_scale_tidal_power_system_feeds_electricity_to_the_national_grid__/ |url-status=dead |archive-url=https://web.archive.org/web/20080727045035/http://www.marineturbines.com/3/news/article/10/world_s_first_commercial_scale_tidal_power_system_feeds_electricity_to_the_national_grid__/ |archive-date=2008-07-27 |website=Marine Current Turbines}}</ref> It generated 1.2&nbsp;MW for between 18 and 20&nbsp;hours a day while the tides are forced in and out of [[Strangford Lough]] through the Narrows.<ref name="technology">{{cite news |author=Brittany Sauser |date=2008-07-29 |title=Tidal Power Comes to Market. A large-scale tidal-power unit has started up in Northern Ireland |publisher=Technology Review Inc., [[Massachusetts Institute of Technology]] |url=http://www.technologyreview.com/Energy/21142/ |accessdate=2008-07-30 |archive-url=https://web.archive.org/web/20080804110058/https://www.technologyreview.com/Energy/21142/ |archive-date=2008-08-04}}</ref>

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.<ref name=mct1>
{{cite news
 | url= http://www.marineturbines.com/3/news/article/11/delay_in_commissioning_one_of_seagen_s_rotors/
 | title= Delay in commissioning one of SeaGen's rotors
 | publisher= Marine Current Turbines
 | date=2008-07-22
 | accessdate=2008-07-30}}
</ref> Full power operation was finally achieved on 18 December 2008.<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/northern_ireland/7790494.stm|title=Tidal energy system on full power|date=2008-12-18|publisher=BBC|accessdate=2009-06-25}}</ref>

Marine Current Turbines was sold to [[Siemens]] in 2012. Siemens sold the company and technology to rival Atlantis Resources ([[SIMEC Atlantis Energy]]) in 2015.<ref name="Hydropower 2015">
{{cite news
 | url=http://www.hydroworld.com/articles/2015/05/atlantis-strikes-deal-to-acquire-marine-energy-tech-company-from-siemens.html
 | title=Atlantis strikes deal to acquire marine energy tech company from Siemens
 | publisher=Hydro Review
 | date=2015-05-01
 | accessdate=2018-02-05}}</ref>
The power generation system was shut down, decommissioned, and removed in stages between 2016 and 2019.<ref name="BBC 2016">
{{cite news
 | url=https://www.bbc.com/news/uk-northern-ireland-35416282
 | title=Strangford tidal energy turbine to be removed
 | publisher=BBC 
 | date=2016-01-27
 | accessdate=2017-06-25}}</ref><ref name=":0" />

==Technology==
SeaGen generator weighed {{Convert|300|MT|LT|abbr=on}}.<ref name=channel4/><ref name=telegraph>
{{cite news
 | url= http://www.belfasttelegraph.co.uk/news/environment/worlds-first-as-16312m-turbine-installed-
 | title= World's first as £12m turbine installed in Strangford Lough
 | newspaper= Belfast Telegraph
 | date=2008-03-31
 | accessdate=2008-07-30}}
</ref> It consisted of twin axial-flow rotors, each driving a generator through a gearbox like a hydro-electric or wind turbine. The gearboxes were three-stage, with two planetary and one spur, giving a 69.8:1 speed increase.<ref name=":1">{{Cite web |date=2007-08-01 |title=MCT goes down to the sea again |url=https://www.modernpowersystems.com/features/featuremct-goes-down-to-the-sea-again/ |access-date=2024-01-05 |website=Modern Power Systems}}</ref> The turbines rotated at around 12&nbsp;rpm, each with a 16&nbsp;m diameter (200&nbsp;m² swept area). Adding two rotors doubled the power, for less than twice the cost. MCT were thus considering further multi-rotor systems in future, e.g. six 24&nbsp;m diameter rotors were claimed to generate over 8&nbsp;MW.<ref name=":1" />

The SeaGen turbines had a patented feature by which the rotor blades can be pitched through 180&nbsp;degrees allowing them to operate in both flow directions – on ebb and flood tides. The company claimed a [[capacity factor]] of 0.59 (average of the last 2000 hours). The power units of each system were mounted on arm-like extensions either side of a tubular steel monopile some {{convert|3|m|ft}} in diameter and the arms with the power units could be raised above the surface for safe and easy maintenance access.<ref name="engineering" /> The SeaGen was built at [[Belfast|Belfast's]] [[Harland and Wolff|Harland and Wolff's]] shipyards.<ref name="guardian">
{{cite news
 | url=https://www.theguardian.com/environment/2008/mar/31/tidal.power
 | title= Tidal power comes to Northern Ireland
 | author=Henry McDonald 
 | newspaper= Guardian
 | date=2008-03-31
 | accessdate=2008-07-30}}
</ref>

==Environmental impact==
[[Image:Strangfordloughmap.jpg|thumb|right|{{convert|400|e6impgal|m3|order=flip|abbr=unit}} of water flow in and out of [[Strangford Lough]] twice a day.]]
SeaGen had been licensed to operate over a period of 5&nbsp;years, during which it was accompanied by an [[environmental monitoring]] programme to determine the precise impact on the marine environment.<ref name=erwin>
{{cite web
 |url         = http://www.all-energy.co.uk/UserFiles/File/2007DavidErwin.pdf
 |title       = Environmental monitoring, liaison and consultation concerning the MCT Strangford Lough Turbine
 |author      = David G Erwin
 |accessdate  = 2008-07-10
 |url-status     = dead
 |archiveurl  = https://web.archive.org/web/20081011132433/http://www.all-energy.co.uk/UserFiles/File/2007DavidErwin.pdf
 |archivedate = 2008-10-11
}}
</ref> No major impacts on marine mammals were detected in three-years of operational monitoring. Seals appeared to avoid the device, or transit passed at slack water when the turbine was not generating (i.e. not turning). While there was some small-scale displacement of marine birds, overall numbers in the Strangford Narrows did not change.<ref>{{Cite report |url=https://tethys.pnnl.gov/sites/default/files/publications/Final_EMP_report_SeaGen.pdf |title=SeaGen Environmental Monitoring Programme. Final Report |last=Royal Haskoning |date=16 January 2011 |id=9S8562/R/303719/Edin |via=Tethys}}</ref> 

{{clear left}}

==References==
{{Reflist}}

==External links==
{{stack|{{Portal|Northern Ireland|Water|Renewable energy}}}}
<!-- *[http://www.seageneration.co.uk/ Sea Generation Ltd] -->
*[http://www.marineturbines.com/ Marine Current Turbines Ltd].

{{Electricity generation in Ireland}}

[[Category:Tidal stream generators]]
[[Category:Tidal power stations in Northern Ireland]]
[[Category:Scottish inventions]]