BUSINESS RULES

IUK provides services to its customers, the Shippers, such that they can transport gas between the IBT and IZT locations or store gas within the Interconnector pipeline. The pipeline is connected to National Grid’s National Transmission System (NTS) and the SILK Pipeline at IBT, and to Fluxys’ Transmission System at IZT.

Shippers using the Interconnector pipeline must adhere to a set of Business Rules and use the Interconnector Shippers Information System (ISIS®) to communicate their flow and/or storage requirements to IUK.

CAPACITY

Each Shipper has rights to capacity within the Interconnector pipeline and capacity rights can be traded between existing Shippers or to new Shippers. Subject to operational conditions and capacity usage, additional interruptible capacity rights may be made available by Interconnector.


MATCHING

To flow gas, Shippers’ requirements must be supplied by both the Interconnector Shipper and their counter-party in the adjacent transportation system. Matching data that is fully or partially matched is used as the basis for creating a Shipper’s Nominations.

NOMINATIONS

A nomination, based on matching data, is the quantity of gas that the Shipper wishes to flow into or out of the Interconnector pipeline, with the ownership of the gas transferring between the Interconnector Shipper and the Shipper in the adjacent transportation system at the entry or exit point.

SCHEDULED QUANTITIES

Under normal operating conditions, Interconnector will flow gas to ensure that all nominations are met. Under certain circumstances, it may not be possible for Interconnector to meet all Shippers' nominations. The scheduled quantity represents the amount of gas Interconnector intends to flow on behalf of a Shipper.


ALLOCATION

The amount of gas flowed through the pipeline is metered and allocated to Shippers based on their scheduled quantities.


VARIABLE INVENTORY & BALANCING

Inventory (or line-pack) is the amount of gas within the Interconnector System. All such gas is owned by Shippers who have both an entitlement and an obligation in relation to the quantity of gas in the system. Shippers’ entitlement/obligation is proportionate to their capacity rights and, subject to the inventory limits that apply at any given time, a Shipper can vary the amount of inventory they hold in the pipeline and can trade inventory with other Shippers.

As the available system flexibility is apportioned amongst Shippers, it is they who have the primary responsibility for maintaining the transportation system in balance. Shippers are provided with all necessary information (including forecast inventory levels based on latest nominated requirements and specific advance warning of any forecast breach of a limit) to maintain their inventory levels within the specified limits at all times.

On an exceptional basis, IUK may take balancing actions if Shippers allow their inventory to move outside the specified limits, and thereby put the service provision to other Shippers at risk. The costs (or revenues received) of any such balancing actions will be passed onto the relevant Shippers.


FLOW TRANSITIONS

The Interconnector can flow gas either from IBT to IZT or from IZT to IBT. A Flow Transition is the process of changing the flow direction of the Interconnector pipeline. Interconnector manages the physical operations associated with flow transitions, including flow scheduling with connected transporters, to ensure that Shippers' commercial requirements are met.


FURTHER INFORMATION

For a more comprehensive description of the Business Rules see:

Outline of Interconnector Business Rules (pdf version)   (63K)

For a description of the contractual arrangements between IUK and Shippers see:

Summary of the Standard Transportation Agreement

For more information on ISIS® see:

Interconnector Shippers Information System (ISIS®)

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