Outputs from the Long Term Development Statement Reforms Working Group

Reports, plans and updates
Publication date
Industry sector
Distribution Network
Transmission Network
Generation and Wholesale Market

There is a clear need for publicly-available distribution grid model data which can more effectively support the connections process and network planning to allow us to reach our net zero goals. By providing accessible, high quality, machine readable information which improves network visibility, we can encourage the deployment of flexible assets by helping to support connections and operations.

The Long Term Development Statement (LTDS) requires Distribution Network Operators (DNOs) to provide network planning data mandated through their licence conditions (SLC25). The LTDS reforms commenced in August 2021, through an industry working group (LTDS WG). They concluded in April 2023, delivering a proposed updated set of data standards implementing the Common Information Model (CIM) for this data requirement.

The outputs from the LTDS WG development process are captured in this package of documentation, made up of the following technical documents:

  • LTDS Grid Modelling Guidelines: these overview the grid modelling approach and detail the grid model data requirements of the LTDS CIM revision
  • LTDS Data Exchange Specifications: these outline the detailed information and requirements related to the exchange of LTDS grid model data using the CIM

Supporting artefacts can be found in the Appendices. Appendix 1 and 6 are available upon request, please contact us at flexibility@ofgem.gov.uk.

The guidance provided in these documents is not mandatory at this stage, and LTDS data should continue to be provided as per the current Form of Statement. We intend to take the proposed changes through a consultation process to gain wider stakeholder input. The consultation is likely to suggest a first phase implementation in April 2024.

Ofgem would like to take the opportunity to thank all those who have contributed to the success of the LTDS Reforms project. This includes thanking our delivery partners at Open Grid Systems and their consortium of experts who have led on the technical delivery, and we are grateful to all working group members for their engagement and valuable input.

Subsidiary documents