Strategic Wider Works

As part of the RIIO-T1 price control we put in place a mechanism to allow Transmission Owners to bring forward large investment projects – known as Strategic Wider Works (SWW) – where funding had not been awarded as part of the price control settlement.

This mechanism allows us to consider the need and funding for these projects during the price control period, so that delivery of these outputs can be brought forward in a timely manner.

The transmission licensees have identified in their business plans a number of projects that they consider are suitable for future consideration under the Strategic Wider Works arrangements.

Other projects which meet the eligibility criteria, set as part of the price control, may also be brought forward.

Approved SWW projects

Since April 2013 we have approved three SWW projects:

Potential SWW projects

The annual Network Options Assessment (NOA) report, published by the GB System Operator in March 2016, identified several network reinforcement options as potential SWW projects in future. The next NOA report will be available in January 2017. 

The North West Coast Connections project wasn’t included in the 2015 NOA due to timing issues. This is a potential SWW project and we are currently assessing an initial needs case submitted by National Grid.

Project name


Earliest in service date

Western Isles link

Either a 450MW or 600MW HVDC link between the Isle of Lewis and Beauly, comprising 80km of land cable and 76km of subsea cable.


Orkney Islands link

An AC subsea cable rated at around 200MW between Orkney and northern Scotland.


Shetland Islands link

A 450MW of 600MW HVDC Link between Kergord on Shetland and Caithness, or alternatively landing in Morayshire.


Beauly Blackhillock

A new 400kV double circuit overhead line between Beauly and Blackhillock, following the existing Beauly –Knocknagael – Blackhillock line.


East Coast onshore upgrade

An upgrade of the existing 132kV onshore network either at 275kV (or 400kV).

2020 (or 2022)

Dumfries and Galloway Strategic Reinforcement

This option involves a new 400kV double circuit between Auchencrosh and Harker, comprising a 180km new overhead line.


Eastern link

A subsea 2000MW HVDC cable. Options for link with vary with different combinations of cable drop off and landing points between Peterhead, Torness, Hawthorn Pit and Lackenby .


Hinkley Seabank Connection Project

A new 400kV double circuit overhead line between Hinkley Point and Seabank.


North West Coast Connection

A new 400kV double circuit connection for a proposed new nuclear power plant in Moorside.


    Publications and updates

    • Published: 19th Dec 2013
    • Factsheets
    • 1 Associated documents
    This factsheet provides an overview of the SWW arrangements for our wider stakeholders.  If you would like any further information on the SWW arrangements please see our latest

    • Published: 21st Oct 2013
    • Guidance
    • 1 Associated documents
    This provides an overview of the SWW arrangements for stakeholders.  It gives detailed guidance to Transmission Owners (TOs) on how to prepare submissions under SWW.  It also encourages TOs to make complete and timely submissions to inform our assessment...

    • Published: 28th Jun 2013
    • Decisions, Other
    • 1 Associated documents
    SHE Transmission submitted a proposal for a new transmission link between the Western Isles and the mainland. This letter explains our decision to send it back for further relevant information that we need to conduct an SWW Needs Case assessment.