FREQUENTLY ASKED QUESTIONS

Here you’ll find answers to some of the most frequently asked questions about Five Estuaries Offshore Wind Farm.

We’ll update these throughout the development of the Project.

About Five Estuaries Offshore Wind Farm 

Extensions to operational wind farms have proven to be a successful way of efficiently developing more offshore generating capacity. In February 2017, The Crown Estate launched an opportunity for existing wind farms to apply for project extensions. This opportunity closed in May 2018, with eight project applications received UK-wide. Seven of those were successful including the proposed Galloper extension, now known as Five Estuaries.

Five Estuaries is  currently in the development stage and must obtain a development consent order first. A Development Consent Order includes detailed environmental and technical assessments to inform our proposals and also includes extensive consultation on, and resulting any refinement of, the proposals.

RWE are leading the development of Five Estuaries on behalf of the project partners.

RWE represents change, innovation and sustainability. As one of the world’s leading generators of electricity from renewable energy sources, we aim to be carbon-neutral by 2040 and to enable a sustainable life for people around the world.

Five Estuaries is owned by a number of shareholders, and RWE Renewables UK is leading the development of the project on behalf of the project partners.

The Project partners are; RWE (25%), a Macquarie-led consortium (25%), Siemens financing arm, ESB (20.83%) and Sumitomo Corporation (20.83%).

RWE

RWE is one of the largest renewable energy generators in the UK, with a diverse portfolio of onshore and offshore wind projects, hydro and biomass with a combined installed capacity of over 2.79 GW (pro rata) (4.8 GW installed capacity.) RWE’s largest contribution to renewable energy generation is from offshore wind projects. RWE, the largest power producer in the UK, accounts for around 15%. of all electricity generated in the UK, a figure that is projected to expand as their renewables portfolio grows.

Macquarie-led consortium

Macquarie Asset Management is a global asset manager that aims to deliver positive impact for everyone. Trusted by institutions, pension funds, governments, and individuals,

Macquarie Asset Management provides access to specialist investment expertise across a range of capabilities including infrastructure, green investments, real estate, agriculture & natural assets, asset finance, private credit, equities, fixed income and multi asset solutions.

Macquarie Asset Management is part of Macquarie Group, a diversified financial group providing clients with asset management, finance, banking, advisory and risk and capital solutions across debt, equity, and commodities.

ESB

ESB has been Ireland's foremost energy company since it was established in 1927, driven by an unwavering commitment to power society forward and deliver a net zero future for our customers and the communities we serve. We have been investing in Britain since 1993, providing flexible, low carbon and reliable electricity generation as well as public EV charging and low carbon business solutions.

Launched in 2022, its Driven to Make a Difference: Net Zero by 2040 strategy sets out a clear roadmap for ESB to achieve net zero emissions by 2040. It also commits ESB to a Science Based Target for 2030 to provide assurance that we are decarbonising our operations at the necessary pace and scale.

As a strong, diversified utility, ESB operates across the electricity market, from generation through transmission and distribution, to supply of customers in addition to using our networks to carry fibre for telecommunications. ESB has a regulated asset base of approximately €10.9 billion (comprising ESB Networks €8.8 billion and NIE Networks €2.1 billion), a 33% share of generation in the all-island market and supply businesses supplying electricity and gas to over 1.9 million customer accounts throughout the islands of Ireland and Great Britain.

As at 31 December 2021, ESB Group employed over 7,800 people.

Sumitomo Corporation

Sumitomo Corporation (SC) is a leading Fortune 500 global trading and business investment company with 131 locations (Japan: 20, Overseas: 111).
The entire SC Group consists of 893 companies. SC conducts commodity transactions in all industries utilizing worldwide networks, provides customers with financing, serves as an organizer and a coordinator for various projects, and invests in companies to promote greater growth potential. SC’s core business areas include six business units: Metal Products; Transportation and Construction Systems; Infrastructure; Media and Digital; Living Related and Real Estate; and Mineral Resources, Energy, Chemical and Electronics, and one initiative: Energy Innovation.”

SC’s corporate message, “Enriching lives and the world”, was created to encapsulate their vision for sustainability in the next 100 years. SC’s business, as well as relationships with stakeholders, has expanded on a global scale. Their mission is to grow sustainably alongside society, pursue development for the world, and enable better lives for all.

RWE is helping to shape the sustainable future of the world’s power supply. As part of society and a key player in the worldwide energy market, we are aware of the responsibility that goes with our role. Corporate Responsibility is part of the contribution RWE makes to sustainable development and responsible business management. Everything from environmental protection and climate-change mitigation, social concerns and human rights through to responsible corporate governance is taken into account. Here you will find links to our corporate reasonability reports and key information. 

Certificates and guidelines (rwe.com) 

Please also see below link to RWE’s non-financial performance in the area of Environment, Social and Governance (ESG) as rated by independent agencies.  

Ratings and rankings (rwe.com) 

Regulatory process and project coordination

Five Estuaries is currently engaged in the government-led Offshore Transmission Network Review, which is looking into ways that the offshore network is designed and delivered, consistent with the ambition to deliver net zero emissions by 2050. Both the Government’s recent Energy Security Strategy and Net Zero goals show the importance of bringing 50GW of new offshore renewable generation online by 2030.

Following the Project’s involvement with the Offshore Transmission Network Review and the feedback from our last stage of consultation, we have now identified the opportunity to coordinate more closely with the North Falls Offshore Wind Farm project. The primary goal of this coordination is to reduce the potential impact of building the onshore connection to the national electricity transmission network for the two projects.

Five Estuaries is also considering submitting an application for a Development Consent Order that would allow for flexibility to accommodate a coordinated connection at a later date, provided there is greater certainty on the commercial, regulatory and technical environment. The viability of any coordinated connection is dependent on the progress made by the Offshore Transmission Network Review process and associated regulatory and commercial policy changes and the individual offshore connector projects involved.

It is important to recognise the risk of delaying projects that the UK Government is counting on to deliver their 2030 ambitions for offshore wind deployment. Alongside considering opportunities for cooperation, we will continue to develop coordinated plans on the basis of existing regulations to provide an onshore connection, ensuring no delay to our planned grid connection date and therefore continuing to support the UK Government’s 2030 targets.

You can read more about the Review here: www.gov.uk/government/groups/offshore-transmission-network-review

Working together to streamline design and minimise local impacts as far as possible is important to both Five Estuaries and North Falls.   

An important consideration for Five Estuaries during the site selection and design work has been the proximity of the proposed North Falls Offshore Wind Farm. Although North Falls and Five Estuaries are two separate projects each requiring their own Development Consent Order (DCO) application and being developed by different shareholder groupings, co-ordination between the two projects has been increasing as the projects become more developed. In support of this, both parties signed a ‘good neighbour agreement’ in summer 2023, which has enabled closer liaison, information sharing and joint planning.  

The primary goal of this coordination is to reduce any potential impacts of building the onshore connection to the national electricity transmission network for the two projects. This meant that Five Estuaries sought to identify suitable options for the Project’s onshore infrastructure that could accommodate either the Five Estuaries project alone or co-location with North Falls.   

Through coordination, we have been able to:  

Almost fully align the onshore export cable corridors;  
Identify possible shared works accesses and construction compounds;  
Exchange data and share surveys e.g.  ecology and archaeology;  
Agree on a shared location for each projects’ substation and identify possible shared access and screening concepts;  
Continue joint engagement with landowners;   
Share our navigational risk assessments and measures to ensure vessel co-ordination during construction; and  
Exchange information on project design at an early stage to carry out cumulative seascape, landscape and visual impact assessments.  

Closely aligning the onshore cable routes, substation locations, and landfall areas for the projects has reduced the amount of land required to build and operate both projects, as well as creating the possibility of reducing potential construction impacts through coordinated works.   

We will continue to explore coordination opportunities to reduce impacts, support local skills and create employment opportunities.   

You can find out more about North Falls at
northfallsoffshore.com

Following consideration of a number of potential options, the Project identified a location for its onshore substation adjacent to the proposed National Grid substation zone. This was based on consultation feedback alongside engineering and environmental considerations.  

Five Estuaries was offered a connection into a new East Anglia Connection Node (EACN) substation by National Grid Electricity System Operator (ESO). The siting of the EACN, where the project connects into the national electricity transmission system, was undertaken by National Grid Electricity Transmission (NGET).  NGET identified a location on the Tendring Peninsula in Essex, which could be integrated as part of the Norwich to Tilbury reinforcement project, as an economic and efficient site for the EACN as set out in the Corridor and Preliminary Routeing and Siting Study published by NGET in 2022.  

Five Estuaries and Norwich to Tilbury are being developed in parallel with the same ambition to be operational by 2030. Throughout the development the project teams meet regularly to share updates on the designs and explore opportunities for coordination to reduce impacts on local communities. Should both projects receive development consent these efforts will continue throughout the construction and operational phases.   

National Grid Electricity Transmission (Sea Link), North Falls (Offshore Wind Farm) and Five Estuaries (Offshore Wind Farm) have been working together to explore the potential for offshore coordination as part of the Offshore Transmission Network Review (OTNR) 'Early Opportunities' workstream.  

In early December 2024, the projects acting together in a consortium led by North Falls, welcomed the decision from the Department of Energy Security and Net Zero (DESNZ) to provide grant funding through the Offshore Coordination Support Scheme (“OCSS”). The aim of the scheme is to develop and explore the feasibility of coordinated options for offshore transmission infrastructure. 

The consortium are currently undertaking a series of studies and assessments to determine the feasibility, challenges and solutions to enable a co-ordinated offshore connection. This work will consider the economics, engineering & regulatory challenges, logistics and programme delivery aspects. The first step will be a high-level feasibility study which is expected to be available before the end of March 2024. 

At this stage, it is too early in the process for Tarchon Energy to have developed enough proposals that allow us to coordinate. We are in dialogue with them and sharing information as appropriate. 

Offshore

The Project will be located to the east of the existing Galloper Wind Farm, approximately 37km at its closest point to the coast of Suffolk in the southern North Sea. There are two proposed array areas for the Project that are located to the north and south of the existing shipping traffic separation scheme. The array areas comprise the Northern Array, which will cover 66.9 km2 and the Southern Array, which will cover 61.2 km2.

This will depend upon the scale of wind turbines available at the time of construction. For the purposes of assessing environmental impacts for our application, the Project has considered a range of options of: 

Fewer taller turbines - up to 41 turbines at up to 399m high or;  
More smaller turbines – up to 79 turbines at up to 320 m high.  

Turbine models available on the market now might not be in production at the time of construction, or more efficient models might be available. However, in line with trends in the offshore wind industry as a whole, and the significant improvements seen over the past five years, it is expected that the turbines will be larger than those installed at neighbouring Galloper Offshore Wind Farm (180m).  

Wind turbine output in megawatts (MW) and size have grown rapidly over the last decade. The Galloper wind turbines installed in 2017 are 6MW units, but already today, wind turbine manufacturers are offering larger turbines. Larger wind turbines have been a key part of making offshore wind a cost-efficient method of electricity generation. Larger models are a key component to this, as the required number of foundations and cables reduces if the wind turbines are larger. However, to generate the increased power per wind turbine, the swept area and therefore height of wind turbines increases. 

For Five Estuaries we have allowed for future development in turbine technology and projected increase in size of wind turbine to ensure the Project can utilise the latest technology and produce cost efficient power for consumers. 

Wind turbines until recently have had design lifetimes of 20 to 25 years, principally as certain components are heavily fatigue loaded. Advancing wind turbine technology means longer design lifetimes are beginning to be possible, and this is something the Project will investigate as it progresses. Our assessment has therefore allowed for possible future development and is based on an anticipated lifetime of the turbine of between 24 to 40 years. 

Onshore

The combined construction corridor for both Five Estuaries and North Falls is proposed to be predominantly 90m wide rather than 200-250m. Each of the onshore circuits required to connect the wind farm are made up of three power cables, each laid within a plastic duct.

Two approaches will be used to lay the ducts; open cut trenching and trenchless techniques such as horizontal directional drilling. For open trenching, a smaller width would be required, of around 60m (previously 120m) for both projects, or around 40m for Five Estuaries alone (previously 60m). The corridor width increases in key areas where significant trenchless crossings are proposed, allowing for different installation options and routeing around potential obstacles or sensitive features.

For trenched sections of the onshore cable corridor, the indicative minimum depth of burial from the ground surface to the top of the cable ducting, would be 0.6 metres. Cables will be deeper than this in certain locations, including at Horizontal Directional Drilling locations where the cables would typically be 5-20 metres below the surface.   power for consumers. 

Five Estuaries would aim to minimise disturbance to hedgerows by using gaps in vegetation where possible. Wherever a hedgerow crossing is unavoidable, and the hedge requires removal, the width of the hedge removed will be limited where practicable. All removed hedges will be replaced with locally appropriate species.  In addition, we would plan to avoid burying cables close to major tree roots in order to maintain cable integrity, as well as seeking to avoid potential impacts on the trees.    

When construction work has been completed, the land will be able to be used as before.  

As part of our licensing we would restrict, or require prior approval, for certain development or works over the cables. This will ensure the safety of anyone working near to our infrastructure; maintain the integrity of the cables; and allow for maintenance to be performed on the cables if required.  

The Outline Landscape and Environment Management Plan (OLEMP) will be included within our application. A final design will then be produced and submitted to the local planning authority for approval prior to works. A commitment to this will be included in our application. The final design will need to consider and co-ordinate with nearby projects, e.g. North Falls and National Grid. A mix of species would be used to provide screening. A representation as to how this screening looks is included within the Onshore Landscape Visualisations which is an annex to the Onshore LVIA chapter, which will form part of the application.

Community

In designing the cable route, Five Estuaries has sought to maintain a buffer from residential properties, where environmental and engineering constraints allow, and without conflicting the principles of developing an efficient, coordinated and economical system of electricity transmission. The latter being a requirement for licence holders under the Electricity Act 1989 such as Five Estuaries.  

 

Only those persons holding property interests which are directly affected by the proposed infrastructure, i.e. locations where infrastructure such as cables or the onshore substation will be physically placed or constructed, will be entitled to compensation in accordance with relevant legislation and case law.  

The Project is at too early a stage for any decisions or commitments about the scale or size of a community benefits package to be confirmed. This is typically based on an understanding of the local community alongside the impact of a Project. All of which we are in the process of gathering data and local knowledge to develop our plans and this will be considered as the scheme progresses. 

Community benefits are considered separate to a project application and traditionally are available at the same time as the projects themselves become fully operational. At that point we will have more detail about what the community support will look like and how it will work.

RWE, as the lead developer, takes the issue of health very seriously and relies on authoritative and independent scientific organisations, such as the World Health Organization (WHO) and the UK Health Security Agency (UKHSA), to review the worldwide body of scientific evidence on electric and magnetic fields (EMFs) and health, as well as reviewing the science ourselves.  

Health considerations are given a high priority in the process by which we arrive at any proposals for new routes for electricity connections. Our approach is to ensure that all our assets comply with the guidelines set by Government on advice from the UK Health Security Agency (UKHSA).

Construction

Construction would not commence until we have received a Development Consent Order and a route to market secured), we anticipate that being 2025 onwards at the earliest. We expect construction to start in 2027 and for Five Estuaries to be operational from 2030 supporting the UK Government’s green energy targets of 50GW by 2030.  

The Project is investigating the availability of suitable ports both for construction and for operations during the life of the wind farm. At this early stage of the project, these decisions have not been made but we are continuing to investigate suitable options. 

The construction vehicle access strategy developed for the construction of the Five Estuaries (and North Falls), and the selected routes, seeks to minimise the use of local roads and maximise the use of on-site haul roads. This has been discussed and agreed in principle with Essex County Council.

At the substation, the preferred local road access option (based on optioneering exercises by each project team) is for HGV construction traffic to access the substation from the A120, travelling north up Bentley Road towards the cable corridor, before turning west onto a temporary substation access haul road running alongside the cable corridor. This has been discussed with NGET, who are carrying out their own consultation and assessments.

To accommodate the additional construction traffic movements via the A120 and Bentley Road associated with Five Estuaries (and for North Falls and potentially EACN in the cumulative scenario), a package of mitigation measures has been developed. These proposed measures not only seek to minimise impacts for the properties on Bentley Road but also consider the safety of road users, cyclists and pedestrians. These have been discussed with National Highways and Essex Highways, and include:

  • A120 / Bentley Road junction improvement – widening of the carriageway and the acceleration taper for merging vehicles onto the A120 (required for all three projects);
  • Widening of Bentley Road to between between the A120 and the VE construction accesses on Bentley Road;
  • The Order Limits are wide enough to construct (if proved to be required) a segregated non-motorised user (NMU) path parallel to but separate from Bentley Road. This is subject to the outcome of further surveys and engagement. If required, it would be set back from the road to minimise impact on trees and hedgerows; and
  • Provision of a temporary 40mph speed limit (reduced from 60mph) along Bentley Road from the junction with the A120. This is to mitigate the noise effects of the peak period construction traffic.

It is acknowledged that, given the current vehicle movements (particularly the very low number of HGVs), the changes in traffic movements will be discernable for the residents of the properties along this section of Bentley Road and consequently the DCO Application will be supported by an outline Construction Traffic Management Plan (CTMP) and an outline Workforce Travel Plan (WTP), that will include measures to manage the traffic flows, such as:

  • Coordination between projects to reduce the maximum daily constriction vehicle movements, wherever practicable;
  • Use of satellite car parks (either at Temporary Construction Compounds (TCCs) or similar offsite parking facilities that do not require using Bentley Road) and a shuttle bus service for the construction workforce;
  • Vehicles not waiting or queuing up with engines running on the site or the public highway;
  • Vehicles properly maintained to comply with noise emissions standards;
  • Deliveries will be restricted to be within the working hours;

Outline versions of the Five Estuaries CTMP and WTP will be included with the application, which act as a framework for the versions of these documents developed by the Contractors for use on site during the works. These are to be secured as DCO requirements. Further discussions are planned with affected residents along Bentley Road, which will need to be coordinated with North Falls, and National Grid (depending on their final proposals).

The onshore elements of the Project have been designed in co-ordination with North Falls. The onshore cable routes of the two projects will run adjacent to it and the substations have been co-located in the same location to the west of Little Bromley. This approach allows for opportunities to minimise environmental and community disruption through coordinated delivery.

Three construction scenarios are being considered further:

  • Scenario 1: Five Estuaries proceeds to construction and undertakes the additional onshore cable trenching and ducting works for North Falls as part of a single civils works (ducting for four electrical circuits). Five Estuaries would undertake the cable installation and substation build for its project only (two electrical circuits). The two projects would share access from the public highway for cable installation and substation construction. The projects would utilise and share the same temporary construction compound (TCC) areas for the cable installation works. In scenario 1 either project could advance to construction first and undertake construction work on behalf of the second project.
  • Scenario 2: Both Five Estuaries and North Falls projects proceed to construction on different but overlapping timescales (between 1 and 3 years apart), with civil works undertaken independently but opportunities for reuse of enabling infrastructure e.g. haul roads / site accesses etc. with the other project reinstating.
  • Scenario 3: North Falls does not proceed to construction; or both Five Estuaries and North Falls projects proceed to construction on significantly different programmes (over 3 years apart). In the latter case the significantly different programmes would mean that haul roads and TCC’s are reinstated prior to the second project proceeding. In such case cumulative impacts are for a potential construction period of 6 years+. No reduction in overall impacts for the schemes from sharing of infrastructure.

Five Estuaries will continue to work with North Falls to look at opportunities for coordination during construction to minimise the overall impact of the two projects.

We are also working closely with the Norwich to Tilbury project to explore opportunities for ongoing coordination.

Yes, the Project does not expect to need to use the haul roads once construction at the substation is complete. It is planned that the haul road will be removed, and land reinstated and returned to the landowner.

We understand the importance of maintaining land drainage systems before, during and after construction. We have engaged with landowners on their existing land drainage systems and will ensure that the main works contractor undertaking the onshore cabling works employs the services of a suitably qualified expert. 

For the cable route, there will be temporary drainage installed before construction and permanent measures installed after construction. The onshore substation will have a dedicated drainage design (including attenuation ponds). The temporary haul road from Bentley Road to Ardleigh Road will also have a specific design, as this road will provide more substantial access than the haul roads on the rest of the export cable corridor. 

Drainage principles would be part of the application and designs would be drawn up by the contractor before works commence to ensure water runs into existing drainage systems, rather than just out into the road. This may require us to alter existing drainage systems and/ or undertake works outside of the main cable corridor. These commitments are captured in the Code of Construction Practice.