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  • noa1617

    Network Options Assessment (NOA)

    The NOA is a licence obligation under National Grid’s System Operator (SO) role which has come from the Integrated Transmission Planning and Regulation (ITPR) project. We have published the second NOA publication at the end of January 2017. This also starts the consultation period for the NOA methodology.

    2016/17 NOA publication

    The 2016/17 NOA publication describes the options that the Transmission Owners (TOs) have provided to meet capability requirements on the GB electricity transmission system proposed by our Electricity Ten Year Statement (ETYS) which can be found here. The publication identifies the options that the SO recommends the TOs further develop for this investment year. The development of these options will help the TOs to deliver the right options at the right time to ensure the GB transmission network is fit for the future. The 2016/17 NOA publication is now available to read here.

    In addition to recommending onshore investment, the 2016/17 NOA also features interconnection analysis. The outcome of this market analysis will be to measure the benefits of further European interconnection and to propose an optimum interconnection level to maximise those benefits.


     Network Options Assessment 2016/17
    Contact us

    We are keen to receive feedback for the 2016/17 NOA to further improve the publication to meet your needs. If you would like to contribute to the evolution of NOA, please provide feedback here.

    If you would like to be notified of future NOA publications and its associated methodologies then please register for updates using the form on the right

    • Archive

      We have created an archive for previous NOA Publications and the first NOA IC Report. You can find them by clicking here.

      2017/18 NOA Methodology

      We are pleased to announce we have now submitted our 2017/18 NOA Methodology to Ofgem which can be read here 2017/18 NOA Methodology. We reviewed the fundamentals of how we perform the economic analysis of NOA which has influenced changes in this year’s methodology. These changes are covered in the 2017/18 NOA Methodology but the full report can be read here NOA Methodology Review Report.

      As the NOA is derived from the Network Development Policy (NDP), the two methodologies are similar. We have been reviewing the NDP to ensure alignment with the NOA and have published an updated version for consultation. The consultation runs until 21 August 2017. Aside from formally recognising the NOA delivers part of the NDP output there are no fundamental changes to the NDP. You can find the revised NDP here NDP 2017 for consultation and contact us with any feedback through our email address  

      The NOA methodologies also include the Strategic Wider Works (SWW) methodology, which has not changed since 2015 and can be found here SWW methodology. Both the Offshore Wider Works (OWW) methodology and the NOA for Interconnectors (NOA IC) methodology can be found in the below sections.

      Final NOA IC methodology

      The Methodology for the Network Options Assessment for Interconnectors (NOA IC) has been reviewed following the consultation in July. The final methodology is now available to download here.We are keen to hear your thoughts on the methodology. If you have any questions or feedback please contact us through our e-mail address  

      A methodology webinar was held on Thursday 27th July. The recording can be streamed using the following link.
      Results from the assessments will be available from October.

      Offshore Wider Works

      In addition to the NOA Methodologies, we have our Offshore Wider Works (OWW) methodology that is current. You can see the methodology by clicking here.  

      As offshore wind projects become larger and, more complex and a greater distance from shore, there is opportunity to improve co-ordination and integration of offshore transmission infrastructure. This methodology sets out a route for such projects to be taken forward. As always, we are interested in your feedback and suggestions for improvement and you can contact us on

      Long-term Market and Network Constraint Modelling

      For NOA 2016/17, we have transitioned from using a tool developed in-house, named ELSI (Electricity Scenario Illustrator), to a model procured externally to undertake electricity market and long-term constraint forecasts of the network. This new model is called BID3, it is retailed by Pöyry Management Consulting (, who have enhanced BID3 to include a Balancing Mechanism re-dispatch for Great Britain, thus allowing users to model the impact of GB transmission networks and calculate constraint costs, which we do for the purpose of Cost Benefit Analysis in the NOA.

      A report that explains why we needed to move from ELSI to a new model, why we chose BID3, what we will use the model for and how we ensured the model is the most economic and efficient solution for current and future work, is available here.

      BID3 has been extensively benchmarked against ELSI. Two independent reviewers (Professor Keith Bell, University of Strathclyde and Dr Iain Staffell, Imperial College London) were appointed to review our development work, BID3 configuration and benchmarking. A copy of their report is available here.

      In order to improve transparency, the SO is pleased to provide an updated version of our former optimisation model ELSI, by clicking here. This is populated with updated scenario data. As such the user can gain valuable insight into the rationale behind investment decisions made by the SO in the data used for SO analysis. For reference a user guide is also provided here.

      Please send any comments or questions on the release of this model to