Demand Estimation

Learn about the Demand Estimation process and access data resources associated with it.

Page contents

    What is Demand Estimation?

    We work with the Demand Estimation Sub Committee (DESC) – an industry body comprising Shippers and Transporters – to produce demand models. These models help develop gas demand profiles that are needed for important industry processes.

    The diagram below sets out the parameters we provide, together with how they are used in Gemini and UK Link.


    Resources to help Demand Estimation

    Below, you can find descriptions of each Demand Estimation deliverable, its purpose, and links to resources to find out more. These include our demand models, the gas demand profiles and weather variables. 

    Demand Estimation deliverable Purpose For use in...

    End User Category (EUC)

    Categorising gas consumers by their different usage patterns

    • Demand attribution
    • AQ calculations
    • Capacity invoicing
    • Read estimation

    EUC Demand Model

    To provide a mathematical representation of the behaviours and reactions of gas consumers for each EUC

    • Production of all gas demand profiles (ALP, DAF, PLF)

    Annual Load Profile (ALP)

    Estimating how consumers typically use their gas during a year

    • Demand attribution
    • AQ calculations
    • Read estimation

    Daily Adjustment Factor (DAF)

    Estimating how gas consumers' usage reacts to changes in weather

    • Demand attribution
    • AQ calculations
    • Read estimation

    Peak Load Factor (PLF)

    View An introduction to the PLF

    Understanding how gas consumers will react in the event of extremely cold weather

    • Capacity invoicing

    Composite Weather Variable (CWV)

    View CWV
    (select "weather" from the list)

    Understanding and explaining the relationship between weather and gas consumption

    • Demand attribution
    • AQ calculations
    • Read estimation


    Seasonal Normal Composite Weather Variable (SNCWV)

    Defining a basis for "seasonal normal" weather
    • Demand attribution 
    • AQ calculations
    • Read estimation


    Access to our UK Link secure area

    All UNC parties are entitled to access the UK Link document secure area, which is a secure internal network.

    If you haven’t already done so, you can apply for access.

    Accessing secure documents


    Demand Estimation timetable

    The graphic below sets out the annual cycle for the Demand Estimation process.

    Sample support for EUC Demand Models

    The EUC Demand Models require daily gas consumption data from a sample of customers across all local distribution zones (LDZs). This is currently supported by:

    • samples managed by Xoserve and distribution networks
    • data submitted by eligible Shippers, following the implementation of UNC MOD 654S

    You can find out more about this in the document Provision of NDM sample data (UNC MOD654S)


    Common queries

    The Demand Estimation Sub-Committee (DESC) is responsible for producing the Derived Factors used in Demand Estimation. The DESC responsibilities are defined in Section H of the Uniform Network Code (UNC).

    The core of the analysis work required to calculate the Derived Factors is performed by the Demand Estimation Team at Correla (on behalf of Xoserve).

    DESC is responsible for providing approval at key stages. This includes the final approval which allows CDSP to update the relevant systems with the new Derived Factors for the upcoming Gas Year.

    For more information please read An introduction to the Demand Estimation Sub-Committee hosted by the Joint Office of Gas Transporters.

    Each year the Demand Estimation Team publishes the ‘NDM Algorithms Booklet’. This booklet provides detailed information about the decisions made in developing the Non-Daily Metered (NDM) algorithms for each gas year.

    The end-to-end demand modelling process is presented as ‘Sections’ in the booklet and include:

    • Data Aggregations: The disposition of the NDM sample sites used in the regression analyses

    • Modelling Results: A summary of the results for the single year modelling runs

    • Algorithm Performance: A review of performance for the NDM algorithm applicable for the last full gas year.

    The NDM Algorithms Booklet is available via UK Link secure documents.*

    (Folder 18. NDM Profiling and Capacity Estimation Algorithms/choose Gas Year/folder 4. NDM Algorithms Booklet)

    *Access to secure links are only available to gas shippers and transporters. To gain access find out about accessing secure documents.

    The anonymised sample Daily Gas Consumption Data can be accessed via UK Link secure documents.*

    (Folder 18. NDM Profiling and Capacity Estimation Algorithms/choose Gas Year/folder 2. Demand Estimation Sample Data)

    The folder contains a ‘README’ document which provides guidance on the structure and contents of the files.

    *Access to secure links are only available to gas shippers and transporters. To gain access find out about accessing secure documents.

    View all Demand Estimation deliverables

    You can find our key deliverables, including models and profiles, in folder 18 of the UK Link secure area. 

    UK Link secure area

    Latest derived factors

    Access the latest End User Categories, Annual Load Profiles, Daily Adjustment Factors and Peak Load Profiles in our derived factors folder. 


    Demand Estimation support

    If you have any questions about Demand Estimation, raise a support request.

    Raise a support request