Case Study

Power Transmission Appraisal (UK)

National Grid has been asked to provide a connection into the National Electricity Transmission System (NETS) for the proposed 3.2 GW Moorside nuclear power station, to be built near Sellafield in West Cumbria and for a number of new wind farms in the Irish Sea. This project is an important step towards meeting National Grid’s challenge to modernise and extend the country’s existing energy infrastructure. Its development is essential to ensure energy security in years to come, and to meet the UK’s carbon reduction targets.

Along with UK energy policy, these proposals also align with the wider Masterplan for Britain’s Energy Coast. This is a £2 billion package of regeneration projects that aims to establish West Cumbria as a major national hub for low carbon and renewable energy generation.

While there is a distribution system serving homes in West Cumbria, there is currently no transmission system to allow the connection of new energy generators to the NETS. The objective is to find the best way to reinforce the national electricity transmission system to provide the required new connections while maintaining a secure and reliable system that can support electricity users at all times.


Cumbria and Lancashire, UK


National Grid



Project Objectives:

To undertake Level 1 & Level 2 Strategic Options Appraisal, routeing and siting studies for transmission equipment to connect proposed nuclear power generation and offshore wind farms on the coast of Cumbria and Lancashire to the existing high voltage transmission system. The study area includes areas  offshore and potential routes through/around the Lake District National Park and across/around Morecambe Bay.

Our Role

Environmental and socio-economic appraisal of potential overhead line connections and substation/convertor station sites.

Activities: SLR has undertaken:-

  • Preparation of the Scoping Report for the Strategic Options Appraisal
  • Level 1 Strategic Options Appraisal of the six strategic options
  • Preparation of the Preliminary Strategic Options Report
  • Feasibility study to look at the routeing of HVDC cables onshore
  • Outline Routeing of new overhead transmission corridors (approx. 190km)
  • Outline Siting of new and/or expanded substations, converter stations, sealing end compounds (SECs) and grid supply points (GSPs)
  • Feasibility study to identify areas where mitigation may be required
  • Preparation of Level 2 Scoping and Methodology
  • Input to studies to identify buildability and interaction with the DNO’s distribution system
  • Preparation of Draft National Grid Methodology for Siting of Non Linear Electricity Infrastructure

Deliverables: Since 2010, SLR has delivered and contributed to the following outputs:

  • NWCC Project Scoping of Strategic Options Appraisal
  • NWCC Preliminary Strategic Options Report
    • Attendance at key stakeholder meetings, workshops, topic group meetings, one-to-one meetings and MP briefings
    • NWCC Project Stage 2 Scoping of Route Corridor and Infrastructure Site Area Identification Studies and Scoping of Route Corridor and Infrastructure Site Area Options Appraisals

Consultation: SLR has contributed to an open and engaging programme of facilitated dialogue from the outset initially primarily focused on key stakeholders involving consultation with a diverse range of statutory and non-statutory organisations from the North West and North East regions.