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: 17th Nov 2017
  • Decisions
  • 1 Associated documents
Blue Transmission London Array Limited – Decision on exceptional event claim submitted under Amended Standard Condition E12-J4.

  • Published: 24th Jul 2017
  • Guidance
  • 1 Associated documents
This updated guidance sets out the cost assessment process that we follow to determine the transfer value for offshore electricity transmission projects.

  • Published: 31st May 2017
  • Decisions
  • 1 Associated documents
Publication of our determination in relation to a notice of an income adjusting event from Gwynt y Mor OFTO.

  • Published: 31st May 2017
  • Decisions
  • 1 Associated documents
Publication of our determination in relation to a notice of an income adjusting event from Thanet OFTO Limited.

  • Published: 26th May 2017
  • Decisions
  • 1 Associated documents
Our decision sets Offshore IDC for 2017/18 and sets out the arrangements for IDC for cap and floor interconnectors in Windows 1 and 2.

  • Published: 4th Apr 2017
  • Open letters and correspondence
  • 1 Associated documents
Blue Transmission Sheringham Shoal Limited – our letter on a contingent event adjustment claim submitted under Amended Standard Condition E12-J3.

  • Published: 3rd Apr 2017
  • Decisions
  • 1 Associated documents
Gwynt y Môr OFTO plc - Direction under paragraph 10 of Amended Standard Condition E12-J4

  • Published: 21st Dec 2016
  • Closed: 27th Jan 2017
  • Consultations and responses
  • 5 Associated documents
Ofgem minded-to position on Interest During Construction for Offshore Transmission and Interconnectors granted the Cap and Floor Regime for 2017/18.

  • Published: 6th Dec 2016
  • Reports and plans
  • 1 Associated documents
This report provides an overview of the revenue earned by each OFTO in the regulatory year to 31 March 2016.

  • Published: 27th Oct 2016
  • Decisions
  • 1 Associated documents
This letter sets out the Authority’s determination not to grant Blue Transmission London Array Ltd £1.7 million as an Income Adjusting Event.