The Emergency Curtailment Quantity (ECQ) process relates only to sites (System Exit Points) curtailed as part of a Gas Deficit Emergency. The ECQ process assigns the quantities of gas associated with emergency curtailment actions undertaken by Transporters as a Trade Nomination between National Grid NTS, as residual system balancer, and each User.
The objective of the ECQ process is to ensure that shippers imbalance positions for the day are unchanged if Transporters curtail the offtake of gas at sites as part of a Gas Deficit Emergency.
The calculation of the Emergency Curtailment Quantity (ECQ) is defined within UNC TPD Section Q 6 as "The quantity of gas (in kWh) which the Transporters, in aggregate, reasonably estimate that Users would have offtaken from the Total System at System Exit Points in respect of which Emergency Curtailment has occurred but for the fact that Emergency Curtailment had occurred at those System Exit Points"
For every affected User, the ECQ value is calculated as the aggregate quantity of emergency curtailment which has occurred, less any quantity of User commercial interruption at the relevant sites. See the "Shipper Curtailment" information below for further details on commercial interruption.
Details of how ECQ is calculated are contained within the ECQ Methodology which can be found on the Joint Office website.
Further information on Emergency arrangements can be found on the Emergency pages.
This process flow provides a basic summary of the ECQ process:
A summary of the process - including communications - can be viewed on the High Level Overview process flow document.
The NTS report is referred to as the "Transporter ECQ Report" on the ECQ High Level OverviewIn addition, where NTS System Exit Points have been curtailed, National Grid NTS will endeavour to provide relevant users with a site specific report detailing the method used to calculate the ECQ. This is referred to as the "NTS ECQ Report" on the ECQ High Level Overview.
If a user chooses to interrupt a site, the relevant transporter should be notified via a P70 form.
Sites which are subject to a P70 will be excluded from ECQ calculations.
For more information regarding the P70 process please read the following guidance document.
P70 and P71 Notices and the Emergency Curtailment Calculation. Q: Should I issue a P70 to the appropriate control room for any commercial relationship I enter into that has the direct effect that a site ceases its consumption of gas ? Yes, the information will assist control room operations and minimise shipper exposur