The project

​Offshore Projects Elements​ ​

Maximum number of turbines

207 offshore wind turbines

Individual turbine capacity

7.0MW and 8.0MW

Nacelle (hub) height

Between 82-122 metres above mean high water spring tides (MHWS)

Turbine rotor diameters

Between 120 - 200 metres (depending on the size of turbine used)

Maximum blade tip height

Up to 222 metres above MHWS

Turbine clearance above mean sea level

At least 22 metres above MHWS

Water depth

Between 21 and 55 metres below LAT at the wind farm site

Foundations
(wind turbines and offshore substation)

The following foundation options are being considered (the chosen option depending on the size of the selected turbines and a number of other variables):

  • Pile driven or drill/driven single steel monopole (cylindrical steel tube);

  • Gravity base (similar to a concrete foot);

  • Piled steel jacket (metal matrix of cross joints); or

  • Steel jacket on suction caissons (steel foot that sucks itself into the sediment during installation).

Inter-Array network, substation and Transmission

Up to three offshore substations would be constructed within the wind farm connected to the wind turbines by inter-array cables of 33 to 66kV.

Up to five subsea export cables, each of up to about 96km in length, running from the offshore substations to landfall, each with a voltage between 132 and 220 kV (these would be HVAC – high voltage AC cables). The offshore export cables would be jointed to the onshore cables at the transition joint bay located in the vicinity of the landfall.

Offshore construction

The offshore construction works would take up to four and a half years to complete; foundation installation (i.e. piling/driving etc.) is anticipated to be completed in 24 months (based on 207 turbine positions), with a maximum of four monopiles installed in a 24 hour period.

Safety zones will be applied for around construction vessels (typically 500m) and turbines (typically 50m) during the construction phase.

The wind farm will have a life span of approximately 25 years.

 

 

​Onshore Project Elements
​Cable landfall   ​​The offshore cables will make landfall in the vicinity of Middleton Sands, within Morecambe Bay where they will be jointed to the onshore underground cables in transition joint bays. The cables at the landfall will be installed by horizontal directional drilling (“HDD”) beneath the saltmarsh and sea defence.
​Onshore cable worksThe offshore cables will make landfall in the vicinity of Middleton Sands, within Morecambe Bay where they will be jointed to the onshore underground cables in transition joint bays. The cables at the landfall will be installed by horizontal directional drilling (“HDD”) beneath the saltmarsh and sea defence. ​Onshore cables will run a distance of about 3.7 km from landfall to the onshore substation. All of the onshore cables will be installed underground, mostly using open cut trenching techniques (maximum width of 3.6m and 3m deep). Either HDD or open cut trenching will be used to cross roads, with the method statement to be agreed with the Highways Authority.
Every 600-1,200 m along the onshore cable route there will be a jointing bay (each jointing bay will be maximum of 30m2 (3 x 10 m) and 2 m deep). There will be a maximum of 30 jointing bays.

The working area (working width) of the onshore cable route corridor will be up to 30 m wide. Temporary construction compounds will also be created along the onshore cable route.

The maximum construction duration for the onshore cable works will be 18 months.
​Onshore substation ​The onshore substation will be located to the east of the proposed NGET Middleton Substation, and will have a footprint of up to 28,900m2. It will include the equipment required to transmit power from the offshore wind farm to the grid and is likely to include the following:
  • Onshore transformers (likely to be 400/220/16kV);

  • Reactors (likely to be connected on 220kV);

  • High Voltage gas insulated switch gear systems;

  • Static VAR compensators (SVC) or static synchronous compensator (STATCOM) (likely to be connected on 16kV); and

  • Harmonic Filters (HF)

Local flood risk will be mitigated by building between 5.1m and 6m above ordnance datum (AOD).

The main components for the onshore substation are likely to be delivered by sea to a local port but with components may also be delivered by road.

There will be up to a maximum of 1000 piles used during construction, with up to 12,935 two way HGV movements. Working hours will be 7am-7pm, except for Sundays and public holidays. Construction will take a maximum of 25 months.