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Information provision for winter 09/10. Jenny Phillips – GNCC Strategy & Support Manager. Agenda. Safety & introductions Review of last winter New Safety Monitor methodology Walk through some data to establish actions Model Interactive session. Winter 08/09. Gas Balancing Alert.
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Information provision for winter 09/10 Jenny Phillips – GNCC Strategy & Support Manager
Agenda • Safety & introductions • Review of last winter • New Safety Monitor methodology • Walk through some data to establish actions • Model • Interactive session
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.
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
Demand and GBA Position January 5th 2009 462 to 472 as 2nd Isle Of Grain entry point commissions.
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
Demand and GBA Position January 20th 2009 429 to 414 to reflect established IUK export behaviour IUK continues to export high volumes
Demand and GBA Position February 3rd 2009 414 to 434 to reflect IUK supply behaviour IUK re-established as a supply into the UK
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
Happy stock level reduces to less than 2 days at max deliverability Therefore 20 mcm removed from GBA Trigger level
But overall storage deliverability doesn’t change …until stock level reduces below max daily deliverability
Storage Deliverability = SM Deliverability requirement Demand > GBA Trigger
Safety Monitor • To allow safe operation of network on a peak day when supplies exceed demand, during a 1 in 50 winter • Two components: • 1st day would required high deliverability to allow “protected by isolation” demand to be disconnected • 2nd day onwards requires lower volume, with 60 days duration, to meet demand which is “protected by monitor”
Coldest day of 1 in 50 winter…..490 mcm/d demand? Market response to price makes ~ 450 mcm/d a more realistic demand level
Demands during isolation ~450 mcm, a realistic maximum for demand at start of isolation process First 24 hours of isolation
Supplies Load above 340 mcm/d must be met by storage 340 mcm/d non storage supply level
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
What if storage deliverability monitor is breached? Assuming only 40 mcm/d of storage deliverability is left…. 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
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