CHAPTER VI

INTERRUPTIBLE CAPACITY

Allocation of interruptible services
Article 32
1
As from 1 January 2018, transmission system operators may only offer standard capacity products for interruptible capacity of a duration longer than one day if the corresponding monthly, quarterly or yearly standard capacity product for firm capacity was sold at an auction premium, was sold out, or was not offered.
2
Transmission system operators shall offer a daily capacity product for interruptible capacity in both directions at interconnection points where the respective standard capacity product for firm capacity was sold out day-ahead or was not offered. At unidirectional interconnection points where firm capacity is offered only in one direction, transmission system operators shall offer at least a daily product for interruptible capacity in the other direction.
3
If interruptible capacity is offered, this shall not be detrimental to the amount of firm capacity on offer. Transmission system operators shall not set aside capacity that can be offered as firm capacity in order to offer it as interruptible capacity.
4
To the extent interruptible capacity products other than daily products are offered, the same standard capacity products for firm capacity shall also apply for interruptible capacity, in terms of duration of the products.
5
To the extent interruptible capacity is offered, it shall be allocated via an auction process with the exception of within-day interruptible capacity.
6
Within-day interruptible capacity shall be allocated by means of an over-nomination procedure.
7
Within-day interruptible capacity shall only be allocated when firm capacity, whether technical capacity or additional capacity, is sold out.
8
Where auctions are held for any interruptible products longer than within-day transmission system operators shall, if known, publish the amounts of interruptible capacity on offer before the start of the auction process.
9
If offered, interruptible capacity shall be allocated by means of a separate auction after firm capacity of equal duration has been allocated, but before the auction of firm capacity with a shorter duration starts, with the exception of within-day interruptible capacity.
10
If offered, interruptible capacity auctions shall be conducted in accordance with the same design principles and timescales as applied for firm capacity. The exact auction dates to be used for the interruptible capacity auctions shall be detailed within the auction calendar with the exception of within-day interruptible capacity. For the annual yearly, all annual quarterly and all rolling monthly capacity auctions, the transmission system operators shall notify network users about the amount of interruptible capacity to be offered one week before the auction starts. Where an auction of firm capacity has not closed on the scheduled start day for the interruptible auctions, the interruptible auctions shall open no later than the next business day after the closing of the respective auctions of firm capacity. In such cases, any change in the offered amounts shall be notified at least 12 hours before the start of the respective interruptible capacity auction.

Minimum interruption lead times
Article 33
1
Transmission system operators must—
a
decide minimum interruption lead times jointly with adjacent TSOs that are transmission system operators; and
b
endeavour to decide minimum interruption lead times jointly with adjacent TSOs that are non-UK TSOs.
2
The default minimum interruption lead time for a given gas hour shall be 45 minutes after the start of the re-nomination cycle for that gas hour. Where a transmission system operator and an adjacent TSO wish to shorten the lead time for interruptions, any related agreement entered into between the transmission system operators shall be subject to competent national regulatory authority approval.

Coordination of interruption process
Article 34
The transmission system operator that initiates the interruption shall notify the relevant adjacent TSO. ... Transmission system operators shall notify their respective affected network users as soon as possible, but with due regard to the reliability of the information.

Defined sequence of interruptions
Article 35
1
The order in which interruptions shall be performed, if the total of nominations exceeds the quantity of gas that can flow at a certain interconnection point, shall be determined based on the contractual time stamp of the respective transport contracts on an interruptible basis. In case of an interruption, transport contract coming into force earlier shall prevail over transport contract coming into force later.
2
If, after applying the procedure provided for in paragraph 1, two or more nominations are ranked at the same position within the interruption order and the transmission system operator does not interrupt all of them, a pro rata reduction of these specific nominations shall apply.
3
To accommodate the differences between the various interruptible capacity services ... transmission system operators shall implement and coordinate the joint procedures provided for in this Article on an interconnection point by interconnection point basis.

Reasons for interruptions
Article 36
Transmission system operators shall include reasons for interruptions either directly in their interruptible transport contracts or in the general terms and conditions that govern these contracts. Reasons for interruptions can include but are not limited to gas quality, pressure, temperature, flow patterns, use of firm contracts, maintenance, up- or downstream constraints, public service obligations and capacity management deriving from congestion management procedures.
Art. 33(1) substituted (31.12.2020) by The Gas (Security of Supply and Network Codes) (Amendment) (EU Exit) Regulations 2019 (S.I. 2019/531), reg. 1(2), Sch. 4 para. 23(2); 2020 c. 1, Sch. 5 para. 1(1)
Words in Art. 33(2) substituted (31.12.2020) by The Gas (Security of Supply and Network Codes) (Amendment) (EU Exit) Regulations 2019 (S.I. 2019/531), reg. 1(2), Sch. 4 para. 23(3); 2020 c. 1, Sch. 5 para. 1(1)
Words in Art. 34 substituted (31.12.2020) by The Gas (Security of Supply and Network Codes) (Amendment) (EU Exit) Regulations 2019 (S.I. 2019/531), reg. 1(2), Sch. 4 para. 24(2); 2020 c. 1, Sch. 5 para. 1(1)
Word in Art. 34 omitted (31.12.2020) by virtue of The Gas (Security of Supply and Network Codes) (Amendment) (EU Exit) Regulations 2019 (S.I. 2019/531), reg. 1(2), Sch. 4 para. 24(3); 2020 c. 1, Sch. 5 para. 1(1)
Words in Art. 35(3) omitted (31.12.2020) by virtue of The Gas (Security of Supply and Network Codes) (Amendment) (EU Exit) Regulations 2019 (S.I. 2019/531), reg. 1(2), Sch. 4 para. 25; 2020 c. 1, Sch. 5 para. 1(1)