The Neart na Gaoithe (NnG) offshore wind farm is being developed approximately 15.5km off the Fife coast in Scotland, UK.
Estimated to cost approximately £1.8bn ($2.4bn), the 450MW offshore wind power project is jointly owned by EDF Renewables UK (50%) and Irish energy company ESB (50%).
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The onshore construction works were started after reaching the financial closure on the project in November 2019, while the first phase of offshore construction was started in August 2020.
Expected to be fully operational by 2023, the Neart na Gaoithe wind farm is expected to generate sufficient power for approximately 375,000 Scottish homes, while offsetting approximately 400,000 tonnes (t) of CO2 emissions a year.
The NnG wind farm will supply electricity at a tariff rate of £114.39/MWh for a period of 15 years under a contract for difference (CfD) signed in February 2015. The lifespan of the wind farm is estimated to be 25 years.
Location and site details
The Neart na Gaoithe offshore wind farm will spread over an area of approximately 105km² in the Firth of Forth off the Fife coast in south-east Scotland.
The Firth of Forth was chosen as the preferred location based on its marine environment, water depth, proximity to port facilities, and estimated energy yield.
Neart na Gaoithe offshore wind farm make-up and infrastructure details
The NnG offshore wind farm will be equipped with 54 Siemens Gamesa SG 8.0-167 DD turbines with a tip height of 208m. The foundations will be laid at a water depth of up to 55m with the turbines planned to be spaced approximately 1km apart from each other.
Saipem’s semi-submersible crane vessel S7000 will be utilised for the installation of casings for piles and seabed preparation. The WaveWalker 1 walking jack-up barge carried out geotechnical survey for the project.
Siemens Energy Management Division’s Offshore Transmission Module (OTM) and High Wind’s Boom Lock system are being utilised for the installation of wind turbine components.
An operations and maintenance (O&M) base for the Neart na Gaoithe wind farm will be located at Eyemouth Harbour.
The 1,040m² main building of the O&M base will be a three-storey building, while the 538m² storage warehouse will be a two-storey facility.
Power transmission
The electricity generated by the turbines will be gathered and transmitted through 66kV inter-array cables connecting two offshore substations (OSS). The offshore substations will be connected with each other through an interconnector cable.
The electricity from the offshore substations will be transmitted through two 37km-long export cables making landfall in the Thorntonloch Beach in East Lothian. From the landfall point, an onshore cable will run underground for a distance of 12.3km to transmit the electricity to an onshore substation near the Crystal Rig onshore wind farm in the Lammermuir Hills.
Financing
The debt financing for the Neart na Gaoithe offshore wind farm project is being provided by 25 financial institutions. LBBW London Branch Project Finance provided £103m ($134m).
Contractors involved
Siemens Gamesa Renewable Energy (SGRE) will supply wind turbine generators, which will be assembled at the Port of Dundee.
Saipem will supply and install the turbine foundations as well as steel jacket foundations for the offshore substations while BiFab will build some of the steel jacket foundations.
GE Renewable Energy Grid Solutions is responsible for the supply of two offshore substations and electrical design work.
The supply and installation of the export cables, both offshore and onshore, will be performed by Prysmian. VolkerInfra will install the 220kV underground cable and fibre optic cable as part of a subcontract awarded by Prysmian PowerLink.
Deme Offshore was awarded the engineering, procurement, construction and installation contract for the inter-array subsea cables, while Fred Olsen Windcarrier was selected for the transportation and installation of the turbines.
Corstorphine + Wright Architects provided design services for the O&M building, which will include the office, warehousing and staff welfare facilities for the wind farm.
GeoSea was contracted for the installation of wind turbine components including offshore transmission module (OTM) developed by Siemens Energy Management Division and High Wind’s Boom Lock system at sea.
Cathie provided geophysical and geotechnical survey consultancy, seabed risk management, and ground modelling services for the Neart na Gaoithe offshore wind farm project.
StormGeo was appointed to provide weather intelligence and advanced data science, while Partrac was involved in conducting marine surveys off the Fife coast.
Neart na Gaoithe wind farm background
The Neart na Gaoithe offshore wind farm project was previously proposed by Mainstream Renewable Power, which was awarded exclusive rights by The Crown Estate to develop the project in 2009.
The grid connection was secured in 2010 and the Scottish Government’s Strategic Environmental Assessment team considered the project in 2011.
Mainstream filed an application to build the wind farm in 2012. The planning permissions for the onshore and offshore elements were granted in June 2013 and October 2014, respectively, and the company secured the CfD from the UK Government in February 2015.
French utility EDF Group, through EDF Renewables UK, acquired the project from Mainstream in May 2018, while ESB purchased a 50% share in the project in November 2019.
EDF Renewables received the updated consent for an improved design of the NnG wind farm from the Scottish Government in December 2018.
