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The Transport-Distribution interface

L’interface entre le réseau de transport et le réseau de distribution correspond à un ou plusieurs points de livraison à un réseau de distribution.

  • What is a PITD?

    The Transport Distribution Interface Point (PITD) is a flow allocation point between the Transmission Network Operator (GRT) and the Distribution Network Operator (GRD).

    Each PITD is determined in relation to the distribution network subzones and the Upstream Transmission Network Operator’s tariff terms. It is in the PITD subzone that the quantity of energy transported over the distribution network for each supplier is reconstituted.

    To each community corresponds one PITD and one only (except Calais and Villereau due to the presence of two different gasses, and Saint-Maximin and Vouneuil sous Biard due to the specific configuration of the network).

    The table of PITDs is published on the GTG 2007 website (french only).

    GrDF updates this table. When an ELD (local distribution company) acts as a new Public Service Distribution platform, it sends all the data to its professional association (SPEGNN), which then provides these data to GrDF.

    The table data emanating from GRTgaz is sent to the GRD by the regional contact assigned

    The codification of the PITD is determined jointly by GRTgaz and the GRD based on the codification guideline defined in the framework of the GTG 2007.

  • Standard capacity


    The standard subscription system consists in allocation by the GRT of transmission capacity (CGlobale) to the PITD up to the “1-in-50” severe demand peak capacity evaluated by GRTgaz in its winter analysis, plus the expected evolution of consumption over the upcoming year on the relevant PITD.

    Operationally, this means automatic allocation month by month of transmission capacity subscriptions to the PITD CO on the basis of:

    • data provided by the GRD;
    • and a coefficient A, which guarantees convergence between operational capacity CO and the global capacity CGlobale.

    This process is broken down into three steps:

    • Step 1 =
      The shippers are bound to first provide GRTgaz with a document called a “joint declaration”, which confirms the tie between the Transportation Transmission Contract (CAT)/Distribution Transmission Contract (CAD)/PITD.
      schema joint declaration
    • Step 2 =
      The GRDs provide the following data to GRTgaz for each Distribution Transmission Contract:
      • 1. Capacity subscribed by the distribution shipper for all delivery points referred to as “non-profiled or with a subscription”, tariffs T4 and TP;
      • 2. Annual reference consumption (CAR) and profile for all delivery points referred to as “profiled or without a subscription”, tariffs T1, T2 and T3.
    • Step 3 =
      GRTgaz can then automatically allocate the transmission capacity to the relevant shippers on the basis of the data provided by the GRD, on the one hand, and the joint declarations provided by the shippers, on the other. The level of capacity allocated by GRTgaz is calculated as follows:
      • 1. For any delivery point referred to as “profiled or without a subscription”, the transmission capacity will be equal to A x Zi x CAR:
        A being an adjustment coefficient related to the winter analysis;
        Zi being an adjustment coefficient related to the customer’s profile and the peak “1-in-50 demand” temperature for the relevant PITD’s weather station;
      • 2. For any delivery point referred to as “non-profiled or with a subscription”, the transmission capacity will be equal to the capacity subscribed by the shipper with the GRD.

      Coefficients A and Zi are determined and published on 1 April of every year : see GTG 2007 website (french only).

    Each shipper present at a PITD will automatically receive an allocation of transmission capacity corresponding to the capacity allocated on the distribution side regardless of the subscription period (annual, monthly or daily). Due to the GRTgaz’s network structure, this transmission capacity is broken down into three terms:

    • 1. Delivery capacity for the PITD,
    • 2. Transmission capacity on the transmission network,
    • 3. Exit capacity from the principal network.

    Feedback from the GRD to GRTgaz

    The standard subscription system is based on monthly feedback of data (capacity subscribed, CAR and profiles by distribution shipper) from the GRD to GRTgaz. This feedback of data can take place according to a number of scenarios.

    • 1. Active GRD: The GRD has created a database that describes its entire customer portfolio (i.e. each customer connected to the distribution network is assigned a Profile/CAR pair or a delivery capacity):
      • Every month, the GRD provides the data (capacity subscribed/CAR/profiles) for all of its customers;
      • GRTgaz allocates capacity for all the PITD to the relevant shippers.
    • 2. Inactive, downgraded GRD: When a database with the profiles of the delivery points does not exist or only exists partially:

      If only the historic shipper is present on the relevant GRD’s network (inactive GRD):
      • The GRD is not bound to provide GRTgaz every month with the data on its customers (capacity subscribed/CAR/profiles);
      • GRTgaz allocates to the shipper, who supplies gas to the historic supplier, all the peak daily consumption defined by GRTgaz and the GRD.
      If a number of suppliers are present on the relevant GRD’s network (downgraded GRD):
      • Every month, the GRD provides GRTgaz exclusively with the data (capacity subscribed/CAR/profiles) of customers supplied by “alternative” suppliers;
      • GRTgaz:
        - Allocates to each of the shippers that supplies a alternative supplier its transmission capacity calculated according to the rules set out above;
        - Allocates to the shipper that supplies the historic shipper capacity equal to the total peak daily consumption defined by GRTgaz and the relevant GRD further to network studies, less the sum of the standard capacity allocated to the other shippers.

  • Exchanges of information on the PITD quantities

    The allocation rules for the PITD defined in the framework of the GTG 2007 provide for exchanges of information between the GRD and GRTgaz to allocate quantities of gas transmitted to the PITD to the Shippers. These exchanges take place daily for interim data and monthly for final data.

    The chart above explains the data exchange process between GRTgaz and GRD. These exchanges may take place daily or once per month before the final values have been determined.

    • 1. Every day, GRTgaz provides a global quantity to the GRD for each PITD.
    • 2. The GRD collects the rates from its non-profiled customers connected to its network.
    • 3. The GRD estimates the consumption of the other “profiled” customers.
    • 4. The GRD then calculates a coefficient K, which is used to adjust the quantities supplied by GRTgaz and the quantity consumed on its network.
    • 5. The GRD provides GRTgaz with the quantities broken down by CAD (Distribution Transmission Contract) and by PITD.
    • 6. Based on the joint declaration that binds the Transportation Transmission Contract (CAT) to the Distribution Transmission Contract(s) (CAD), GRTgaz allocates the data to the Transportation Shippers.

  • Inter-operator account (CIO)

    The transportation transmission invoices for the transmission services in Month M are established based on the allocations provided by the GRDs to GRTgaz at the beginning of Month M+1.

    The allocations used for invoicing are not reviewed thereafter even when there is a change in the data that served to calculate the allocations.

    An inter-operator variance account is created to adjust the differences between the new values of the quantities delivered by GRTgaz after the transmission of the take-offs in M+1 and the final take-offs by GRTgaz provided in M+1.

    This variance account in managed in the framework of the Inter-Operator Account Management contract (CIO), a standard document having been established in the framework of GTG 2007. Each distribution network operator signs a contract with GRTgaz.

    For more information:

    Download the Compte d’écart Inter-Opérateurs - french only