Enduring Exit Regime & NTS Risk Management
Processes
Offtake Arrangement Workstream – OAD Section I Review Group 316
Agenda
 Enduring Exit Regime & NTS Risk Management
Processes - Overview
 Real-time Network Modelling Tools
 NTS Risk Management and Constraint Management
 Next Steps Discussion
 Flow Swapping Process
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Constraint Forecasting Overview
OPN Data
DFN Data
On-line Network
Modelling &
Assessment
Constraint
Forecasting &
Identification
Telemetry
Within Day Constraint
Management Strategy
Physical &
Commercial
Constraint
Management Tools
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Risk in the Enduring Regime
 Potential risk generated due to Interruptible NTS
Offtakes becoming Firm NTS Offtakes
 More Offtakes & greater Volatility/System Flexibility
 Zero Exit buyback target and 100% exposure to NG
with no collar on the costs
 No Exit equivalent of an Entry “TFA”. Therefore
constraint management must be carried out BEFORE
the constraint occurs
 Many locations complicates risk analysis and
constraint management decisions
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Risk in the Enduring Regime
 Broadly, there are two main issues that could give rise
to an NTS Exit constraint:
1. The flat supply rate is too low to meet the flat
demand rate in an area of the network and
pressures become critical.
2. The aggregate within day flow variations remove
too much linepack and pressures become critical
 Scenario 2 is driven by the offtake flow profiles,
therefore in order to forecast and mitigate the risk of
this scenario day ahead and within-day, good OPN
data is essential
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Risk Associated with OPN Data
Delayed or
Inaccurate
OPN Data
OPN Data
DFN Data
On-line Network
Modelling &
Assessment
Risk of
DELAYED
Constraint ID
Constraint
Forecasting &
Identification
Telemetry
Risk of
INCORRECT
Constraint ID
Risk of taking
inefficient actions
Within Day Constraint
Management Strategy
Risk of delays,
rendering some tools
useless
Risk of Increased
Constraint
Management Costs
Physical &
Commercial
Constraint
Management Tools
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Constraint Management (CM) Tools
 There are more tools available and no reactive tools
(interruption) to deal with Exit constraints in the
Enduring Exit regime, therefore more time required to
make efficient constraint management decisions
 No constraint management tool will have immediate
effect, each of the tools have differing lead times
 Delayed constraint identification may leave some
constraint management options unavailable/ineffective
 Delayed constraint identification is likely to drive up
constraint management costs
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Potential CM Tools that rely on
OPN Data
Offtake Profile Notice (OPN) Rejection
OPN data required to run process
Flow-Swapping
OPN data required to run process
Offtake Reduction Invitations
OPN data required to run process
Restricting within-day Firm Capacity Release
Day ahead OPN analysis to identify potential constraints
Constrained Storage Utilisation
OPN analysis to identify constraint
Surrendering Daily NTS Exit (Flat) Capacity
OPN analysis to identify constraint
Exit Capacity Constraint Management Agreements
OPN analysis to identify constraint
Locational Buy Actions
OPN analysis to identify constraint
Operating Margins Utilisation
OPN analysis to identify constraint
Off-Peak Capacity Management
OPN analysis to identify constraint
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Benefits of OPN Data Accuracy
Accurate &
Timely
OPN
OPN Data
Data
DFN Data
Increased Model
Accuracy
On-line Network
Modelling &
Assessment
Early
Constraint ID
Constraint
Forecasting &
Identification
Accurate
Constraint ID
Telemetry
More certainty of Capacity Availability
Better FWACV Handling
Within Day Constraint
Management Strategy
Reduced CM
Costs & Risk
Better Gas Quality Forecasting
Increased Efficiency of Compressor Management
Increased Efficiency of OUG & UAG Management
Flow Forecasting for Maintenance Purposes
And more…..
Physical &
Commercial
Constraint
Management Tools
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Benefits of OPN Data Accuracy
 Good within day forecasting will drive down untimely
and exaggerated constraint management instances
 Better on-line network modelling will help deliver more
optimised NTS operation; ultimately reducing NTS
operating costs through efficiency savings (compressor
costs, Emissions, UAG etc)
 Greater certainty of within day capacity availability
means more capacity requests will be fulfilled beyond
what is obligated.
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Summary
Summary
 The enduring exit regime removes the option of interruption from
NTS’s demand management tool kit. As interruption was a close to
real time action this both puts more emphasis on;
 New exit tools – Of which many use OPN as part of their
transaction process. i.e. deviation from prevailing forecast
 Forecasting – the use of these tools will need to be assessed at
longer lead-times to avoid emergency actions and/or the
requirement to curtail exit flows in the first place
 More generally optimal NTS operation will ultimately reduce NTS
operating costs through efficiency savings (compressor costs,
FWACV, UAG etc) through better forward network assessment
 Greater certainty of within day capacity availability means we will be
able fulfil more capacity requests beyond what is obligated.
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Position on Development
 National Grid NTS continues to believe that receiving information
on an offtake by offtake basis on their expected profile is a basic
requirement of the system operator in order to meet its safe,
efficient, economic and co-ordinated licence obligations.
 National Grid NTS would not however be apposed to any changes
to either the OPN format, timing and/or associated restrictions in
flow profiles (groups and/or single offtakes) if they can be shown to
better facilitate these licence conditions between the TSOs.
 Overall, National Grid NTS believes the emphasis of ‘section I’
should be on forecast accuracy of the physical profile notification at
all lead-times and not simply adherence to prevailing data in order
to define allowed ramp rates based on percentage change.
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Next Steps…?
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Flow Swaps – OAD Review
Mike Wassell
Background
 National Grid NTS and the DNOs may initiate flow swaps to
manage their systems economically and efficiently.
 OAD section I 2.4 (refer to final slide)
 Where National Grid NTS or the DNO User request a flow swap
the aggregate of the revised OPN rates for all Offtakes in the same
LDZ / NTS Exit Zone are the same as the prevailing OPN
aggregate rates
 i.e. the mechanism as detailed under OAD Section i is for 1:1 swap
of flow from one offtake to one or more alternative offtakes serving
the same LDZ.
 From the 1st of Oct 2012 DNO User(s) are subject to exit flat
overrun charges and any deemed enduring applications that may
result from a chargeable exit flat overrun.
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Example of Flow Swap
Pre Flow Swap
Flow 10
Flow 0
Exit Point A
Exit Point B
Capacity 10
Capacity 5
National Grid request a Flow Swap from NTS/LDZ offtake A to NTS/ LDZ offtake B of 7
Post Flow Swap
Flow 3
Flow 7
Exit Point A
Exit Point B
Capacity 10
Capacity 5
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Views sought
 Is it felt such a scenario is likely in the enduring regime?
 1-in-20 obligation
 choice of offtakes to swap flow to on majority of cases
 Way forward
 is there a case for change to the flow swap rules?
 Case for change options ?
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NTS Initiated Flow Swap

OAD Section I

2.4 Revisions requested by National Grid NTS
 2.4.1 National Grid NTS may at any time request a DNO to submit revised Offtake Profile Notices for two or more
Offtakes for an LDZ, subject to and in accordance with this paragraph 2.4.
 2.4.2 National Grid NTS' request shall specify:
 (a) the Offtakes in respect of which such revision is requested;
 (b) the times with effect from which the DNO is requested to revise the relevant rates of offtake; and
 (c) the revised rates of offtake requested.
 2.4.3 Any request by National Grid NTS for the revision of any Offtake Profile Notices shall satisfy the requirement that,
for all times in the Day, the aggregate, in respect of all Offtakes (serving the same LDZ) for which such request is made,
of the revised rates of offtake requested is the same as the aggregate rates of offtake under the prevailing Offtake Profile
Notices at the time the request is made.
 2.4.4 To the extent to which the revision by the DNO of any Offtake Profile Notice(s) in compliance with National Grid
NTS' request would infringe any of the requirements of this paragraph 2 or TPD Section J4.5.2, National Grid NTS shall
be deemed to have waived such other requirements (on the assumption that the DNO submits such revised Offtake
Profile Notice(s) within 15 minutes after National Grid NTS' request is made).
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NTS Initiated Flow Swap

OAD Section I
 2.4.5 The DNO shall comply with National Grid NTS' request unless in the DNO's reasonable opinion the safe and
efficient operation of the LDZ (consistent with the DNO's obligations to Users under the Transportation Principal
Document) would be materially prejudiced by the flow of gas at the relevant Offtakes on the basis of the requested
revisions, in which case the DNO shall:
 (a) contact and inform National Grid NTS of the position as soon as possible following receipt of National Grid
NTS' request; and
 (b) cooperate with National Grid NTS and use all reasonable endeavours to agree upon alternative revisions to
Offtake Profile Notices.
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