Offshore transmission

The government set an ambitious target for the deployment of renewable energy over this decade.

By 2020, the government expects 15 per cent of the UK’s total energy needs to be met from renewable sources. This means that around 30 per cent of our electricity may come from renewables.

To achieve this substantial deployment of green energy, the government has established a policy framework to support investment in renewable generation. Within this framework, offshore wind is recognised as being an important source of renewable energy.

Government support schemes will encourage further investment in renewable electricity generation. For this power to reach homes and businesses in Britain, fit for purpose electricity networks must be developed, particularly offshore.

It is estimated that billions of pounds of investment will be needed to connect these projects.

Offshore Transmission Regime

A step change in network investment of this kind calls for a more dynamic approach to the development of transmission networks: an open, competitive approach that is built on encouraging innovation and new sources of technical expertise and finance.

To this end, along with the government, we have established the competitive offshore transmission regulatory regime. It underpins the government’s renewable energy targets by placing the requirements of renewable generators and Britain’s electricity consumers at the forefront.

Our role in Offshore Transmission

Competitive Tender Process

We are responsible for managing the competitive tender process through which offshore transmission licences are granted.

Granting licences to operate new offshore transmission assets via a competitive tender process mean that generators are partnered with the most efficient and competitive players in the market. This should result in lower costs and higher standards of service for generators and, ultimately, consumers.

Offshore Transmission Tenders

Offshore Transmission electronic tendering portal

Please visit the Offshore Transmission Electronic Tendering Portal where you can register to participate in the tender process. If you have any issues registering on the Portal, please contact Daniel Baker (

Past key dates in appointment of Offshore Transmission Owners (OFTOs)

On 22 July 2009 we began the first set of transitional tenders to appoint new offshore grid companies (OFTOs).

Transitional tenders are for projects where the transmission assets have been, or will be constructed by the offshore developer, then transferred to the OFTO.

The second transitional tender round was started on 17 November 2010. Tender Round 3 (TR3), the first tender round to be run under the enduring regime, was launched in February 2014.

Publications and updates

  • Published: 31st Mar 2021
  • Decisions
  • 1 Associated documents
Decision on Interest During Construction (IDC) rates to apply in 2021-22 to offshore transmission projects and interconnectors granted the cap and floor regime.

  • Published: 17th Mar 2021
  • Guidance
  • 3 Associated documents
Certification arrangements in Great Britain following amendments to the ownership unbundling requirements of the Gas Act 1986 and the Electricity Act 1989

  • Published: 28th Jan 2021
  • Decisions
  • 1 Associated documents
This document outlines the Authority’s decision on the exceptional event claim by Gwynt y Môr OFTO plc

  • Published: 18th Dec 2020
  • Decisions
  • 2 Associated documents
The Authority's final decision in relation to the application for certification under the ownership unbundling requirements of the Third Package by Diamond Transmission Partners Hornsea One Limited.

  • Published: 18th Dec 2020
  • Open letters and correspondence
  • 1 Associated documents
A joint letter with BEIS updating stakeholders on our work relating to offshore coordination.

  • Published: 10th Dec 2020
  • Decisions
  • 4 Associated documents
Erratum Notices correcting typographical errors in the licence modification notices issued to Thanet OFTO Limited, TC Ormonde OFTO Limited, Diamond Transmission Partners Walney Extension Limited and TC Lincs OFTO Limited on 17 November 2020.

  • Published: 27th Nov 2020
  • Decisions
  • 1 Associated documents
See our decision on modifications to future Offshore Transmission Licences.

  • Published: 19th Nov 2020
  • Closed: 22nd Jan 2021
  • Consultations and responses
  • 1 Associated documents
We are consulting on if additional changes should be made to help ensure that efficient, fit for purpose competitions are still run within the existing regime.

  • Published: 17th Nov 2020
  • Decisions, Open letters and correspondence
  • 10 Associated documents
Decision on modifications to Offshore Transmission Licences.

  • Published: 4th Sep 2020
  • Decisions
  • 2 Associated documents
The Authority's final decision in relation to the application for certification under the ownership unbundling requirements of the Third Package by TC Rampion OFTO Limited.