ScottishPower Renewables is investigating the potential for a new offshore windfarm in the East Anglia zone, called East Anglia TWO.
The proposed site, being developed by East Anglia TWO Ltd, is located in the southern North Sea approximately 31km from its nearest point onshore; the port of Lowestoft and 32km from Southwold. It would cover an area of 255km2 and would have an operational capacity of up to 900 megawatts which is enough to power approximately 742,413 UK households*.
*Calculated taking the number of megawatts (800) multiplied by the number of hours in one year (8,766), multiplied by the average load factor for offshore wind (36.7 %, published by the Digest of United Kingdom Energy Statistics), divided by the average annual household energy consumption (3,900 kWh), giving an equivalent of powering 659,922 homes.
The proposed East Anglia TWO Offshore Windfarm has the potential to make a substantial contribution to UK 2030 energy targets by meeting nearly 5% of the UK offshore wind cumulative deployment target for 2030.
The offshore development area comprises of:
- Wind turbines – up to 75 wind turbines would cover an area of 255km2. The maximum height to the blade tip would be 300m above sea level.
- Offshore platforms – up to four electrical platforms as well as a meteorological mast and a construction, operation and maintenance platform.
- Subsea cables – up to 200km of inter-array cables connect the turbines to the offshore electrical platform. A maximum of two export cables, buried or protected on the seabed will then transport the electricity to shore. The two cable routing options are the preferred choice in terms of engineering and environmental constraints, in particular avoiding the geological Coralline Crag sea bed feature.
The onshore development area comprises of:
- Landfall location – Horizontal Directional Drilling (HDD) will be required to install the ducts to avoid any construction works on the beach, and a minimum setback distance of 85m from the cliff top will allow for natural coastal erosion based on the potential 100-year erosion prediction and will not compromise the integrity of the cliff.
- Underground cables – a maximum length of 9km. All onshore cables will be buried with no above ground infrastructure left after construction. For the majority of the route, trenching will be undertaken in which to place the ducts through which the cables are pulled. Manhole covers may be required at some locations to allow for maintenance. Where certain features need to be avoided/crossed, HDD techniques may be used to minimise environmental impacts and disruption.
- Public highways – a number of road improvements or modifications could be required to facilitate the safe ingress and egress from the public highways for construction access or at locations on the existing public road network in order to facilitate construction traffic and/or construction-related deliveries.
- Onshore substation – a maximum building height of 15m and external electrical equipment of up to 18m in height is proposed and the substation will cover an area of 36,100m2 (190x190m).
- National Grid substation – to accommodate the electricity produced by East Anglia TWO (and East Anglia ONE North) an Air Insulated Switchgear (AIS) or Gas Insulated Switchgear (GIS) substation would be required. The maximum height of the AIS would be 13m with a footprint of 140x325m and the maximum height of the GIS would be 16m with a footprint of 140x120m.
- National Grid realignment works – one additional pylon within the vicinity of the National Grid substation as well as up to four cable sealing ends and potential additional replacement or upgrade works will also be required for East Anglia TWO (and East Anglia ONE North).
Consultation is a key driver of the EIA process, and continues throughout the lifecycle of the projects, from initial stages through to consent and post-consent. Extensive community and stakeholder consultation has informed the designs (particularly the site selection) and helped to develop environmentally sustainable proposals for East Anglia TWO and East Anglia ONE North.
Phase 1 Consultation (October to November 2017)
- Introduced East Anglia ONE North and East Anglia TWO to new stakeholders
- Consulted on potential constraints to the locations for onshore infrastructure
- Explained the Environmental Impact Assessment Scoping process
- Introduced the projects to those potentially impacted by the visual impacts of the offshore windfarm.
As part of the consenting process SPR submitted Scoping Reports for East Anglia TWO and East Anglia ONE North to the Planning Inspectorate (PINS) for their consideration in November 2017. These Scoping Reports requested a Scoping Opinion to agree the methodology for undertaking the full Environmental Impact Assessment (EIA).
Phase 2 Consultation (March 2018)
- Phase 2 marked the start of statutory consultation which involves engagement with bodies and organisations as required by the DCO process
- It provided further information on the Onshore Study Area within which SPR intends to site the projects’ onshore electrical infrastructure
- Set out the refinement of the study area
- Sought opinions on the viewpoints selected to assess the visual impact of the offshore wind turbines
Phase 3 Consultation (June to July 2018)
- Consulted on the refinement of the Indicative Onshore Development Area
- Presented Zone 7 in Friston as the preferred substation location
- Consulted on mitigation that the projects could adopt, particularly in terms of cable routing and at the substation location
Phase 3 Consultation was designed to focus on consultation regarding the Indicative Onshore Development Area and aimed to gather the community’s views on mitigation.
Phase 3.5 Consultation (October to November 2018)
- An additional phase of consultation to present Broom Covert, Sizewell, as an alternative substation site option
- Explored options to relocate the existing Sizewell C reptile mitigation land
- Proposed improvements to parts of the local road network
- Presented refinement of the proposed area required for National Grid Electrical Transmission (NGET) to connect their proposed substation to the existing Overhead Line
Following this additional phase of consultation, with a primary focus of exploring the viability of an alternative substation site, Grove Wood, Friston was concluded to remain SPRs preferred site location.
Development Process Update
SPR is currently holding Phase 4/Section 42 Consultation on the Preliminary Environmental Information Report (PEIR) for East Anglia TWO (and East Anglia ONE North), this provides a summary of the proposed project, site selection process and the key findings of the Environmental Impact Assessment (EIA) process to date. The purpose of the EIA is to assess and examine the potential impacts of the project on the environment from construction, operation and decommissioning.
As part of the process, a detailed description of the current baseline (existing environment) for all development areas has been identified through a combination of desk based studies, consultation and site-specific surveys. All potential impacts of the project have been assessed and where identified that an impact will be significant, mitigation measures are proposed to avoid or reduce to acceptable levels.
The proposed East Anglia ONE North project is also in the pre-application stage and its application programme runs in parallel with East Anglia TWO, however they will be submitted as separate DCO applications. The proposed onshore development area has been developed to allow for the construction of both projects. At this stage it is not known whether both projects would be constructed simultaneously or sequentially. Therefore onshore topic assessments will include the two cumulative assessment scenarios.
Further refinement of the project design and EIA will be based on consultation responses received in relation to the PEIR. The final results of the EIA will be presented in the ES which will accompany the Consultation Report in the final DCO application.
Upcoming Project Milestones
- Phase 4 / Section 42 Consultation on Draft Environmental Statement – ends 26 March 2019
- Full Development Consent Application – Q4 2019