This website will be decommissioned soon. Our new UK website is now live in Beta.

Please take a look and let us know what you think.
  • Market Operation Data Interface System (MODIS)

  • The National Grid MODIS system (Market Operation Data Interface System) was originally developed to report market data, focusing on provision of data for the European Transparency and REMIT Regulations. 

    MODIS was developed separately from our control room systems to ensure balancing of the system was not compromised. 

    MODIS was subsequently extended to calculate and manage new data flows resulting from BSC Modification P305 for De-Rated margins (DRM) and Loss of Load Probabilities (LOLP) as part of the EBSCR project (Electricity Balancing Significant Code Review).  As a result the MODIS system evolved into a more complicated system used by multiple users for a variety of purposes. 

  • Response to Ofgem's REMIT Investigation

  • Ofgem investigated National Grid Electricity Transmission following the publication of incorrect de-rated margin data between November 2015 and January 2016 to the wholesale energy market.  Today (20th July 2017) Ofgem have published their findings.

    We have cooperated fully with Ofgem’s investigation to explain the cause of the errors and the improvement steps we’ve taken.  For clarity, the data error was fully resolved in March 2016 and our response to Ofgem’s letter details the improvements we’ve made to ensure that our systems and processes are robust and compliant. 

    View Ofgem Investigation Letter:  Ofgem letter

    View National Grid Response:   National Grid response

  • ACER REMIT (P329)

  • The Agency for the Cooperation of Energy Regulators (ACER) has specified new common schema formats for inside information (REMIT) web feeds.

    Modification P329 describes how this will be implemented for GB market participants.  ELEXON have informed OFGEM and ACER that P329 will go-live on 29th June 2017.

    There is an ETR NG – Market Participant Interface Specification which describes the existing format for ETR and REMIT submissions from Market Participants to National Grid (V4.0 further down this page) that has applied since ETR go-live on 5thJanuary 2015. 

    There is a new version of the interface specification (v5.7) which describes the new ACER REMIT format which will apply from 29th June 2017 onwards.  This document is provided below for participants to use for developing and testing the new format submissions ahead of the go-live date. 

    View ETR-ACER REMIT NG-Market Interface Specification v5.7 (for new ACER REMIT format submissions) 

    Please see also ELEXON's June 2017 Release webpage  

    Please see the following user guide for MODIS which includes new screens for ACER REMIT: MODIS User Guide Screens v0.18

  • EBSCR Lessons Learned Report

  • This report provides a summary of the lessons learned from National Grid’s internal Electricity Balancing Significant Code Review (EBSCR) Project.  It includes background information on the MODIS system, timelines, what went wrong and lessons learned and remedial actions.

    View EBSCR lessons learned report

  • National Grid to Market Interface Specification

  • For any queries on this document, please contact the ETR project team.

  • 21 Jul 2014
    Document review form ETR National Grid to Market Interface document version 1 0 Industry comments completed response
    60 KB

  • WSDL files


    • This defines the services to be implemented by the participants. National Grid will implement client applications to invoke services they have implemented.
    • Market Participants will need to change some details in this file and provide National Grid with their updated version of the WSDL. For example, they would need to change things like the Target namespaces and location etc.
    • Note: They are not expected to change the services, operations and parameters etc.


    • This defines the services to be implemented by National Grid. Participants will have to implement client applications to send XML data to MODIS.
    • National Grid will make some changes to this file once the full details are known. For example, the exact name of the Target namespaces and locations etc.
    • Details of authentication will be confirmed in later iterations of the WSDLs.

    Download the WSDLs [.zip]