Hornsea Project Two, North Sea, United Kingdom

Wind turbine

Hornsea Project Two (HP2) is the second offshore wind farm proposed to be constructed within the Hornsea Zone in North Sea, UK. With a proposed installed capacity of 1.8GW, the wind farm is touted to become the biggest of its kind in the world.

The project developer, Dong Energy, gained the rights to the project through the acquisition of SMartWind, a 50:50 joint venture (JV) between Mainstream Renewable Power and Siemens Financial Services, in August 2015.

The scoping report for the project was completed in 2012, while the consent application was submitted to the Planning Inspectorate (PINS) for examination in January 2015, which was completed in March 2016.

The development consent for the project was granted by the Secretary of State for Energy and Climate Change in August 2016. Construction works will commence following the completion of the final investment decision (FID).

The Hornsea Zone

Covering an area of 4,735km², the Hornsea Zone has the potential to generate more than 4GW of renewable energy, which would account for 4% of the overall power generation capacity in the UK, capable of serving approximately three million households.

The zone is situated off the Yorkshire coast, where the normal water depth ranges between 30m and 40m and reaches a maximum depth of 70m. The Hornsea Project Two site is located approximately 89km from the Yorkshire coast, covering an area of 462km² at the centre of the Hornsea Zone.

The zone also hosts the 1.2GW Hornsea Project One, which is scheduled to come online in 2020, while the HP2 and the 2.4MW Hornsea Project Three are proposed.

Hornsea Project Two wind farm make-up

The offshore wind farm will be equipped with approximately 360 wind turbines, each ranging between 5MW to 16MW in capacity.

The turbines will have a maximum upper tip height of 272m and maximum rotor diameter of 250m. Three foundation types are being proposed for the project, including steel monopiles, steel jackets and concrete gravity base.

The project will further involve the installation of inter-array cables and two accommodation platforms at the offshore site.

Transmission and onshore facilities

"The offshore wind farm will be equipped with approximately 360 wind turbines, each ranging between 5MW to 16MW in capacity."

The electrical output from the project is proposed to be conveyed to the 400kV National Grid transmission station at North Killingholme, following the same route of the Hornsea Project One's transmission system.

The project proposes the use of either a high-voltage direct current (HVDC) or a high-voltage alternating current (HVAC) transmission system. If the first option is chosen, the project will involve the construction of six offshore HVAC collector substations and two HVDC converter stations at the offshore site.The HVAC option, on the other hand, will involve the construction of an offshore HVAC collector substation and two offshore HVAC reactive compensation substations.

The landfall for the transmission cable will be located at Horseshoe Point, near the village of North Cotes in Lincolnshire. The HVDC option will require the laying of four onshore cable trenches, whereas the HVAC option will require the laying of eight onshore cable trenches.

Either an onshore HVDC converter station or an onshore HVAC substation will be constructed midway from the landfall to the National Grid transmission station. The facility will be approximately 200m-long, 150m-wide and 40m-high.

The total length of the offshore transmission subsea cables will be 150km, whereas that of the onshore transmission cable will be 40km.

Key players involved

The baseline noise surveys for the project were performed by RPS Group.