1. Information provision for winter 09/10 Jenny Phillips – GNCC Strategy & Support Manager

2. 2 Agenda Safety & introductions Review of last winter New Safety Monitor methodology Walk through some data to establish actions Model Interactive session

3. 3 Winter 08/09

4. 4 Gas Balancing Alert GBA intended to signal that additional supplies/demand reduction may be required to avoid the risk of a Gas Supply Emergency. At day ahead, compare 13:00 demand forecast with GBA trigger level GBA trigger level based on combination of available supply forecast demand impact of a potential breach of Safety Monitor.

5. 5 When is the GBA Trigger level revised? When stock in any individual storage site reaches a level where there is less than 2 days remaining at max deliverability, it is removed from GBA trigger level Revise trigger if there are significant and sustained changes to supplies

6. 6 Demand and GBA Position January 1 st 2009

7. 7 Demand and GBA Position January 5th 2009 462 to 472 as 2nd Isle Of Grain entry point commissions.

8. 8 Demand and GBA Position January 10th 2009 472 to 429 as SRS volumes are removed from GBA Trigger calculation High IUK Export and SRS withdrawals

9. 9 Demand and GBA Position January 20th 2009 429 to 414 to reflect established IUK export behaviour IUK continues to export high volumes

10. 10 Demand and GBA Position February 3 rd 2009 414 to 434 to reflect IUK supply behaviour IUK re-established as a supply into the UK

11. 11 Demand and GBA Post February 3 rd 2009

12. 12 What information was being published?

13. 13 Demand

14. 14 Storage

15. 15 Storage Deliverability

16. 16 Assumptions of Non Storage Supply

17. 17 GBA Trigger

18. 18 GBA Trigger

19. 19 Information is there, but disparate…

20. 20 So how have we built on the experience? Revised safety monitor methodology Raised a corresponding UNC mod for GBA Seeking to put all information together in useful format on web pages

21. 21 The new safety monitor methodology

22. 22 How would this work?

23. 23 Some data… NSSStorage Deliverability (for safety monitor) Total Supplies GBA storageGBA Trigger Happy Storage Stock Happy Storage Deliverability

24. 24 NSSStorage Deliverability (for safety monitor) Total Supplies GBA storageGBA Trigger Happy Storage Stock Happy Storage Deliverability 3431264691264697520 3431264691264695520

25. 25 NSSStorage Deliverability (for safety monitor) Total Supplies GBA storageGBA Trigger Happy Storage Stock Happy Storage Deliverability 3431264691264697520 3431264691264695520 3431264691064493520 Happy stock level reduces to less than 2 days at max deliverability Therefore 20 mcm removed from GBA Trigger level

26. 26 NSSStorage Deliverability (for safety monitor) Total Supplies GBA storageGBA Trigger Happy Storage Stock Happy Storage Deliverability 3431264691264697520 3431264691264695520 3431264691064493520 But overall storage deliverability doesn’t change…

27. 27 NSSStorage Deliverability (for safety monitor) Total Supplies GBA storageGBA Trigger Happy Storage Stock Happy Storage Deliverability 3431264691264697520 3431264691264695520 3431264691064493520 34312146410644915 34310644910644900 But overall storage deliverability doesn’t change …until stock level reduces below max daily deliverability

28. 28 Safety Monitor Deliverability DemandNSSStorage Deliverability Total Supplies GBA storage GBA Trigger Happy Storage Stock Happy Storage Deliverability SM Deliverability requirement 3923437541875418752055 4043437541875418552055

29. 29 DemandNSSStorage Deliverability Total Supplies GBA storage GBA Trigger Happy Storage Stock Happy Storage Deliverability SM Deliverability requirement 3923437541875418752055 4043437541875418552055 3953437541855398352055 GBA Trigger level reduced

30. 30 DemandNSSStorage Deliverability Total Supplies GBA storage GBA Trigger Happy Storage Stock Happy Storage Deliverability SM Deliverability requirement 3923437541875418752055 4043437541875418552055 3953437541855398352055 390343704135539815 55 Storage deliverability reduced

31. 31 DemandNSSStorage Deliverability Total Supplies GBA storage GBA Trigger Happy Storage Stock Happy Storage Deliverability SM Deliverability requirement 3923437541875418752055 4043437541875418552055 3953437541855398352055 390343704135539815 55 40134355398553980055 Demand > GBA Trigger Storage Deliverability = SM Deliverability requirement

32. 32 Safety Monitor To allow safe operation of network on a peak day when supplies exceed demand, during a 1 in 50 winter Two components:  1 st day would required high deliverability to allow “protected by isolation” demand to be disconnected  2 nd day onwards requires lower volume, with 60 days duration, to meet demand which is “protected by monitor”

33. 33 Coldest day of 1 in 50 winter…..490 mcm/d demand? Market response to price makes ~ 450 mcm/d a more realistic demand level

34. 34 Demands during isolation ~450 mcm, a realistic maximum for demand at start of isolation process First 24 hours of isolation

35. 35 Supplies 340 mcm/d non storage supply level Load above 340 mcm/d must be met by storage

36. 36 Isolation Approx. 15 mcm/d of storage deliverability required to isolate load (within day use of linepack minimises requirement) Approx. 40 mcm/d of storage deliverability required to support “protected by monitor load” for first 24 hours Hence safety monitor deliverability requirement is 55 mcm/d. 55 mcm/d storage + 340 mcm/d non-storage supports isolation on a ~450 mcm day

37. 37 What if storage deliverability monitor is breached? Approx. 15 mcm/d of storage deliverability is still required to isolate load This leaves only 25 mcm/d of storage deliverability to support “protected by monitor load” ie a 15 mcm/d shortfall Hence 40 mcm/d storage + 340 mcm/d non-storage can only support isolation on a 450-15 = 435 mcm day Assuming only 40 mcm/d of storage deliverability is left….

38. 38 The Safety Monitor applies to the whole winter…

39. 39 Rest of workshop… Given the information already available, how can we present it in a way which adds value? 5 Day Demand Forecast Safety Monitor Volume Requirement Storage Stock levels Safety Monitor Deliverability Requirement Storage Deliverability level Non Storage Supply assumption

40. 40 Supply/Demand Balance

41. 41 Supply/Demand Balance

42. 42 Use of storage based on max deliverability or “smart” use?