Hornsea offshore wind project is being built off the coast of Yorkshire and the Humber tidal estuary in England, UK. It will be world’s the biggest offshore wind farm, upon full completion.
The project is being developed in three phases, Hornsea Project One, Hornsea Project Two and Hornsea Project Three, by Danish power company Orsted. A fourth phase, Hornsea Project Four, was also proposed by Orsted in October 2018.
Construction of the first phase started in 2016, with operations scheduled to begin in 2020. Orsted announced the divestment of 50% interest in Hornsea Project One to Global Infrastructure Partners in September 2018.
Construction on the second phase is expected to start in 2018, while operations are scheduled to begin in 2022.
Orsted submitted an application for the Development Consent Order (DCO) for Hornsea Project Three in May 2018. The consent decision for the application is expected in 2019, following which construction will begin in late-2020. Hornsea Project Three is expected to commence operations in 2025.
Hornsea Project Four will be developed approximately 65km offshore Flamborough Head located on the Yorkshire coast, if approved. It is expected to cover an area of 860km² and comprise 180 turbines.
Hornsea Project One details
The Hornsea Project One wind farm is being built 120km away from the Yorkshire coast in an area of approximately 407km². It will have a capacity of 1.2GW, with 174 Siemens turbines of 7MW each.
The turbines are 190m-tall and have a rotor diameter of 164m. The foundation of each turbine will have a diameter of approximately 8.1m.
The wind farm will consist of three offshore substations, the first of which was installed in May 2018.
It will have the longest offshore cable route system of 900km length. The offshore cables will be connected to the underground onshore cables through transition joints at Horseshoe Point.
The underground onshore cable route will run 40km from the landfall location to the onshore substation at North Killingholme, where the electricity will be fed to the national grid. The Hornsea Project One is expected to power approximately one million homes in the UK.
Hornsea Project Two wind farm details
Hornsea Project Two will possess a net capacity of 1.4GW and power approximately 1.3 million UK homes. The project site is approximately 89km off the coast of Yorkshire.
The wind farm will consist of 165 8.0-167 DD Siemens turbines, which have a rated capacity of 8MW each. The turbines have a rotor diameter of 167m, swept area of 21,900m² and blade length of 81.5m.Hornsea Project Two infrastructure will also include two offshore accommodation platforms, two offshore high-voltage direct current (HVDC) converter substations, six offshore high-voltage alternating current (HVAC) collector substations, two offshore HVAC stations, and subsea inter-array electrical circuits.
The electricity generated by the wind farm will be collected by the offshore substations and transmitted onshore by 150km-long subsea transmission cables.
"The Hornsea Project One wind farm is being built 120km away from the Yorkshire coast in an area of approximately 407km²."
The cables will transmit the electricity generated to the onshore substation located in North Killinghome. The onshore cables will run parallel to those of Hornsea Project One.
Hornsea Project Three location and make-up
The Hornsea Project Three will be developed approximately 121km off the North Norfolk Coast, in the North Sea. An offshore area of approximately 696km² is being explored to develop the project, which will generate 2.4GW to power more than two million homes.
The wind farm is expected to consist of approximately 300 wind turbine generators. The proposed transmission system will be either high-voltage direct current (HVDC) or high-voltage alternating current (HVAC). The power generated by the wind farm will be transmitted onshore by a 163km-long offshore cable system, which will make landfall at Norfolk coast.
Underground cables will transfer the electricity from the landfall point to an onshore HVAC booster station planned to be built near Little Barningham, and an onshore substation near Swardeston.
The power will be further fed to the national grid at the Norwich Main National Grid Substation. The onshore cable route will be approximately 55km-long and 80m-wide.
Contractors involved with the Hornsea offshore wind project
Fugro GeoConsulting was contracted for carrying out geotechnical investigation for the Hornsea Project One and Hornsea Project Two sites, while A2SEA was contracted for offshore turbine installation.
Tideway was contracted for installing export cables at Hornsea Project One, while Balfour Beatty won a $37m contract to construct an onshore high-voltage substation for phases one and two.
Atkin was contracted for providing engineering design services for Hornsea Project One, while Dragados Offshore was contracted for delivering four substations.
ABB was awarded contracts worth $250m and $150m for connecting Hornsea Project One and Hornsea Project Two respectively to the UK grid. The company was also contracted to equip high-speculation service operations vessels, which will work on Hornsea Project Two with its Onboard DC Grid™ power distribution system.
Siemens Gamesa was contracted for supplying and servicing 165 turbines at Hornsea Project Two in June 2018. The company is also supplying 174 turbines for Hornsea Project One.
Prysmian Group, Baldt Industries, CHC, EEW SPC, Gulf Marine Services, Osbit, Uni-Fly, RPS Group, SeaRoc Group, LOC Group, Ramboll, Semco Maritime, Nexans and NKT are some of the other contractors and suppliers involved in the project.