Winter Update
David Salisbury GCF 25th January 2010
Agenda
Headlines
Background
Process
Types of interruption
Chronology of events
Interruption
How cold was it ?
Implications for the future
Conclusions
Headlines
High levels of demand experienced 4th Jan – 11th Jan
NTS record send out 8th Jan (463 mcm)
4 Gas Balancing Alerts; two potential NGSE
Volume interruption invoked on NGGD networks (EM, NW and EA)
Good response from customers
Continuous review of network operation
All NGGD volume interruption load restored for 9/10; all NSL interruption restored 10/10
Process
Design System
Demand Forecast
Capacity Bookings
Winter Operations Plan
Licence1 in 20 Requirement
Received in May each year
Made through the OCS processProvide signals to NTS wherecapacity required
To flow within design capabilityand booked capacity
Interruption
Types of Interruption
Test – for up to three times a year
Commercial – by shipper
Emergency
Constraint – localised constraint (NSL interruption)
Volume – high level constraint invoked when reach capacity triggers
Chronology (4th – 11th Jan) 4th Jan
very high demand levels forecast for 5th Jan
Forecast to exceed capacity triggers – volume interruption invoked in EM and NW
5th Jan
Continued forecast high demand levels for 6th Jan; exceed capacity triggers – volume interruption in EM, NW
6th Jan
Ditto for 7th Jan but capacity triggers in EA also breached
7th Jan
Modelling data and review of network operation allow increased triggers for 8th Jan
Some volume interruption revoked
8th Jan
Reducing demand allows all volume interruption to be revoked for 9th Jan
9th Jan
Further reducing demand allows all NSL interruption revoked for 10th Jan
Interruption Data
Volume (mcm)
04/10 05/10 06/10 07/10 08/10 09/10 10/10 11/10
EA 0.02 0.04 0.02 0.39 0.02 0.02 0 0
EM 0.07 1.20 2.29 2.57 0.69 0.01 0 0
NW 0.12 1.12 1.12 1.19 0.85 0.08 0 0
No. customers
EA 1 2 1 2 1 1 0 0
EM 1 47 51 52 21 1 0 0
NW 7 45 45 53 38 6 0 0
East Anglia
20.00
22.00
24.00
26.00
28.00
30.00
32.00
Send out
Send out + int
Cap Trig
NSL Trig
East Midlands
East Midlands
30.00
31.00
32.00
33.00
34.00
35.00
36.00
37.00
Send out
Send out + int
Cap Trig
NSL Trig
NorthWest
30.00
32.00
34.00
36.00
38.00
40.00
42.00
44.00
Send out
Send out + int
Cap Trig
NSL Trig
North London
North London
20.00
25.00
30.00
35.00
40.00
45.00
04/01
/201
0
05/01
/201
0
06/01
/201
0
07/01
/201
0
08/01
/201
0
09/01
/201
0
10/01
/201
0
11/01
/201
0
12/01
/201
0
13/01
/201
0
14/01
/201
0
15/01
/201
0
16/01
/201
0
17/01
/201
0
NL
Cap Trig
West Midlands
West Midlands
20.00
22.00
24.00
26.00
28.00
30.00
32.00
34.00
36.00
WM
Cap Trig
How cold was it ?
7 of the 16 coldest days in the last 14 years occurred in w/b 4th JanAverage CWV's
09/0
1/20
10
08/0
1/20
10
07/0
1/20
10
01/0
1/19
97
31/1
2/19
96
06/0
1/20
10
04/0
1/19
97
02/0
1/19
97
07/0
1/19
97
10/0
1/20
10
20/1
2/20
09
04/0
1/20
10
05/0
1/20
10
06/0
1/20
09
03/0
1/19
97
08/0
1/19
97
-2
-1.8
-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
1
CW
V
Implications for 2011 ?
Much reduced interruptible volume post October 2011 because of DN Interruption Reform
Interruptible load reduces to 0.4 mcm
Network reinforcements on track to be completed ahead of 2011
Anticipated fewer NSLs in winter 2010
Valuable data gathered for:
Future demand forecasts
Network capability
Conclusions
Demand Forecast
Close to peak day ?
Valuable information for future forecasts
Interruption
Good customer response (some potential FTIs)
Network Operation
Networks have stood up well