Offshore transmission network review

This review looked into the way that the offshore transmission network is designed and delivered. It concluded in May 2023, and the organisations involved, including the Department for Energy Security and Net Zero, are now implementing its findings to deliver a coordinated offshore transmission regime for Great Britain.

Overview

Offshore wind generation plays a central role in decarbonising our energy system to reach net zero and to meet growing consumer demand.

The UK is aiming to generate 50GW of secure, home-grown offshore wind power by 2030. As we increase offshore wind generation, we will need to reinforce the onshore and offshore transmission network infrastructure to deliver the energy from wind farms at sea to consumers across Great Britain.

We launched the offshore transmission network review (OTNR) in 2020 to ensure that the transmission connections for offshore wind generation are delivered in the most appropriate way, and to find the appropriate balance between environmental, social and economic costs.

The review brought together key stakeholders involved in the timing, siting, design and delivery of offshore wind, to consider all aspects of the existing regime and how this influences the design and delivery of transmission infrastructure.

We have published the review outcomes in a summary report. We are now implementing the review’s findings. Project partners continue to deliver several outputs of the OTNR and we will continue to build on its findings in collaboration with them.

The transmission infrastructure and why we need more of it

To achieve our 2030 ambition, we need to transform Great Britain’s energy system. We are working to enable the most efficient and coordinated grid reinforcement to be delivered by relevant parties, keeping new developments to a minimum. However, the transition to net zero will need to be underpinned by new network infrastructure across GB, both onshore and offshore, to meet the scale and pace of demand, and to transport electricity where it is best placed to be generated, to where it is needed most.

Transmission infrastructure is required to transfer the electricity generated offshore, onshore. Overhead lines, underground cables (in designated areas), substations and sub-sea cables are key components of transmission infrastructure.

How the transmission infrastructure is developed and the government’s role

Development of new transmission infrastructure currently takes 11-13 years and is often on the critical path for connection of new generation. The 2022 British Energy Security Strategy (BESS) committed to significantly reduce timelines for delivering strategic onshore transmission network infrastructure, with an ambition to halve the duration of the end-to-end process by the mid-2020s. This is vital for our renewable energy generation ambition.

The process

  • Government works alongside other bodies such as NESO, NGET and Ofgem to deliver energy infrastructure
  • the Crown Estate and Crown Estate Scotland lease areas of seabed to private developers to design and deliver offshore generation
  • the National Energy Systems Operator (NESO) sets out the high-level design for the necessary transmission through independent, evidenced based assessment
  • developers, often transmission operators such as National Grid Electricity Transmission (NGET) or generator developers such as Orsted, can then make applications to build infrastructure. They must show that their proposals meet the nationally set criteria, and that they have considered alternatives and community views . Each project must hold statutory consultations to take into account community views
  • the government does not make planning applications or choose precise routes for energy infrastructure but does have a robust and independent planning process

Offshore Transmission Network Review (OTNR) closure

The following 2 documents mark the move to implementing the review findings:

Projects that have grid connection offers

The Early Opportunities workstream covers advanced projects with existing connection agreements that were too far advanced to be included in the Holistic Network Design. The Early Opportunities workstream worked with developers on coordinating infrastructure, to deliver near-term benefits to communities and the environment.

To help achieve this, we launched the Pathfinder process. Pathfinder projects were created for projects that are leading the way in utilising the enabling regulatory and policy changes to test processes.

Read more about the Pathfinder status.

Offshore Coordination Support Scheme

We launched the Offshore Coordination Support Scheme (OCSS) in December 2022, a grant fund to enable successful advanced projects to develop feasible coordinated designs that could be put forward for planning application. The scheme closed to applicants in February 2023 and awarded funding to a coordination proposal for the 2023 to 2024 financial year. Based on the findings of the feasibility work funded through the OCSS, we determined not to continue funding for this coordination proposal for the 2024 to 2025 financial year.

Pathway to 2030 and Beyond 2030 publications

The Pathway to 2030 and the Beyond 2030 publications recommended designs for the connection of offshore wind farms.

The Pathway to 2030 report includes the Holistic Network Design. The Beyond 2030 report includes the Holistic Network Design Follow Up Exercise.

The recommendations cover both the on and offshore network, and show how the power should be transported from the wind farms to where it is needed. In some cases, the documents recommend that two or more wind farms should build coordinated connections. This means that the wind farms will share some of the infrastructure needed to transport the power generated by the wind farms.

The relevant publications can be found at the National Energy System Operator’s website.

See also:

What happens next for offshore projects in the Pathway to 2030 and Beyond 2030 publications

While the Pathway to 2030 and Beyond 2030 publications provide recommendations on how to connect offshore wind farms, they are not fixed, detailed plans. For example, the publication can recommend that a wind farm connects to a specific existing substation, but it will not say exactly what route the cables should take between the wind farm and the substation.

The ‘project promoter’ is responsible for building the transmission projects included in the publication. Ofgem are responsible for deciding who is allowed to build which bits of the network.

The project promoter is either:

  • the company that is building the wind farm
  • a company set up specifically to build the offshore transmission (known as an Offshore Transmission Owner, of OFTO), or
  • one of the 3 onshore transmission owners

The project promoter is responsible for undertaking consultation with communities and other stakeholders in accordance with the requirements under relevant legislation. For Development Consent Orders this includes the Planning Act 2008 and Environmental Impact Assessment regulations.

To have your say on the proposed projects, you should participate in the project promoter’s consultation. Project promoters will share information about proposed projects with affected communities.

Future Framework

The Future Framework workstream considers the long-term approach for developing and delivering offshore wind and associated transmission infrastructure for projects connecting from 2030.

In 2021 we consulted on proposals for a new, more strategic end-to-end approach to how offshore wind and associated transmission infrastructure is developed and delivered.

We have considered responses to the consultation and collaborated with OTNR delivery partners to develop 3 key recommendations for a Future Framework for the deployment of offshore wind and multi-purpose interconnectors. The government response to this consultation provides details of the recommendations and actions for implementation.

The key recommendations are:

1. DESNZ will work with project partners to develop a more strategic approach for the deployment of offshore wind and Multi-Purpose Interconnectors.

2. Adopt delivery models to maximise efficiency in terms of cost and risk.

3. Consider the timing of transmission design and delivery.

Initial changes will apply to projects due to become operational by the mid- to late-2030s. The Future Framework will be implemented in a transitional way, with different aspects put in place over time by relevant programmes or activity taken forward by project partners. In the longer-term, the approach will evolve for subsequent projects captured by future iterations of holistic, centralised network planning.

We have published a statement of support from project partners alongside the Future Framework publication, in which project partners confirm their commitment to delivery of the recommendations in line with their existing remits. We will work closely with the Scottish and Welsh Governments to ensure the Future Framework will be implemented in line with devolved functions in Scotland and Wales.

Community engagement

As part of a fair and just transition to net zero, the communities that are hosting future electricity transmission network projects must be recognised for the contribution they are making to support the delivery of cheaper, secure, low carbon energy.

Communities will continue to have a say on any proposals in their area. It is important for this Government that where communities host clean energy infrastructure, they should directly benefit from it.

We are considering ways that ensure communities benefit from living near new onshore electricity transmission infrastructure and are committed to ensuring fair and beneficial outcomes in alignment with our overall mission.

Delivery partners

The OTNR was led by the Department for Business, Energy and Industrial Strategy (BEIS) and its successor, Department for Energy Security and Net Zero (DESNZ), with support and collaboration from a range of government and industrial bodies. We will continue to work with the project partners as we proceed with implementation.

  • The Crown Estate manages the seabed, natural marine resources and much of the foreshore around England, Wales, and Northern Ireland, and is responsible for awarding seabed rights for offshore renewable energy projects
  • Crown Estate Scotland manages land and property on behalf of the Scottish Ministers, with the view to investing in property, natural resources, and people to deliver lasting value for Scotland
  • Defra is the UK government department responsible for safeguarding the UK’s natural environment, supporting its world-leading food and farming industry, and sustaining a thriving rural economy
  • HM Treasury is the government’s economic and finance ministry
  • Marine Scotland manages Scotland’s seas and freshwater fisheries along with delivery partners NatureScot and the Scottish Environment Protection Agency
  • the Marine Management Organisation licenses, regulates and plans marine activities in the seas around England so that they are carried out in a sustainable way
  • the Ministry of Housing, Communities and Local Government is the UK Government department for housing, communities, and local government in England
  • National Energy System Operator is responsible for planning and operating Britain’s electricity and gas networks
  • Ofgem is the Office of Gas and Electricity Markets, a non-ministerial government department and an independent National Regulatory Authority whose role is to protect consumers now and in the future, by working to deliver a greener, fairer energy system
  • the Welsh Government is the devolved government of Wales, representing Welsh interests
  • the Scottish Government is the devolved government of Scotland representing Scottish interests

Documents and resources

Contents