1. Enduring Offtake Arrangements (Including an alternative daily interruptible capacity release mechanism to facilitate use of spare capacity)
Peter Bolitho

2. Off-peak interruptible capacity
Business rules difficult to draft along side daily interruptible capacity.
Main concerns about daily interruptible capacity: - Off-Peak users likely to have to buy firm capacity which may drive unnecessary system investment - Off-Peak users pay too much - Release mechanism – largely use-it-or-lose-it - Does not best facilitate use of “spare capacity” during periods when such capacity is available
Realisation it easier to promote use of “spare capacity”
through re-definition of release mechanism
Theme Date Department

3. Release of Off-Peak Interruptible Capacity for existing exit points
Max SPOR x 24
Baseline?
(existing exit points)
Daily Interruptible
Capacity
Capacity
Holding
Daily Firm Capacity
Enduring Capacity
Theme Date Department

4. Revised Daily Interruptible Release Mechanism
The quantity to be offered will be determined as:
A Use-it-or-Lose-It (UIOLI) amount - the difference between the Firm NTS Exit (Flat) Capacity holdings at the NTS Exit Point and the quantity of NTS Exit (Flat) Capacity that is expected to be utilised by Users for the purposes of facilitating gas flows (assessed from a rolling average over a thirty (30) Day period from D-36 to D-7 inclusive);
Where the Forecast Total System Demand is less than 80% of the 1-in-20 peak day demand, the difference between the Maximum Supply Point Offtake Rate multiplied by 24 and the aggregate Firm Exit (Flat) Capacity holdings (where positive); and
Any additional amount that National Grid NTS may make available at its discretion without jeopardising supplies to Firm NTS Exit (Flat) Capacity holders.
Theme Date Department

5. Re-definition of Daily Interruptible Service would incorporate other key features of the Off-Peak service
NG NTS required to publish by 15:00 hours forecast total system demand as a percentage of the 1 in 20 demand.
User obliged to apply for Enduring Capacity in the July application widow at a level not less than the maximum overrun quantity in the last 12 months.
‘Ticket to ride’ principle enhanced as the sanctions
for overrun are more serious
Theme Date Department

6. Comparison with separate Off-Peak Interruptible Service
Advantages
‘Ticket to ride’ principle enhanced
Allocation on the basis of price where multiple users exist
Easier to draft against the main proposal in terms of allocations and overruns.
Disadvantages
Prices greater than zero mean Off-Peak users pay too much (even greater contribution to fixed costs)
May not be consistent with Regulation 1775 which requires TSOs to offer long-term interruptible services
Removal of traditional interruptible status requires changes to NGG Safety Cases
Theme Date Department

7. Could this approach be adopted in the
Main Proposal?
Theme Date Department