Industry Meeting. 28 th February 2012

Transcription

1 Industry Meeting 28 th February 2012

2 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 2

3 Introduction What is the current situation? Recent conditions in the South Island Security of Supply under the new Code arrangements An overview of recent market behaviour 3

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8 In Summary... Inflows are below average, Storage is below average Prices are above average THE MARKET IS WORKING The Winter is likely to be tight But unlikely to be Security of Supply issues, unless: Major, multiple plant failures, or Worse inflows than the last 80 years AUTUMN / WINTER FORECAST(S) ARE FOR INFLOWS CLOSE TO AVERAGE 8

9 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 9

10 Security of Supply The new SoS arrangements were codified in 2010 A set of functions were transferred to the SO SO functions are: Supply information Implement a Public Conservation Campaign at a particular hydro storage level

11 Supply of Information The SO reports on Security of Supply risk using the Hydro Risk Curves (HRCs) HRCs are a measure of New Zealand or South Island supply risk relative to hydro storage, based on a set of assumptions and historic inflows Assumptions are based on publicly available information and any additional information supplied to the SO on a voluntary basis by asset owners An example of the HRCs are shown overleaf

12 Hydro Risk Curves (South Island)

13 Current position The current storage position is well above the 10% HRC, for both NZ and SI We do not expect any supply issues this winter, based on our assumptions on plant usage and the last 80 years of inflows The spaghetti diagram, overleaf, indicates how we expect hydro storage to behave if inflows this year follow any of the historical inflow sequences since 1932

14 Spaghetti Diagram

15 Regional Supply The codified SoS arrangements link a Public Conservation campaign to either NZ or SI aggregate storage only Regional supply risk is therefore not necessarily reflected in the published HRCs The SO will deal with regional supply problems using normal operational process: - Facilitating operational forums - Efficient use of available transmission - Dispatch of available plant - Grid Emergency Notices as and when necessary 15

16 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 16

17 17 Market Behaviour

18 $/MW $350 Daily Average Price HAYWARDS $300 $250 $200 $150 $100 $50 $ Data from energy market services

19 $/MW $300 Daily Average Price BENMORE $250 $200 $150 $100 $50 $ Data from energy market services

20 GWh 120 Aggregate Daily NZ Demand 7 Day Average Data from energy market services

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22 MW Futures Price and Volumes $200 $180 $160 $140 $120 $100 $80 $60 $40 $20 $0 BEN Vol OTA Vol BEN Price OTA Price Data from d-cyphatrade

23 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 23

24 South Transfer Power System Limits Four distinct power system pinch points 1.Export south out of the Taranaki 2.Transfer from Bunnythorpe to Haywards 3.Transfer over HVDC 4.Transfer into Southland These are shown graphically on the next slide 24

25 South Transfer Power System Limits Otahuhu Huntly Stratford Whakamaru 1 Bunnythorpe 2 Haywards HVDC 3 Twizel Benmore / Waitaki Valley Livingstone 4 Roxburgh

26 South Transfer Power System Limits Otahuhu Huntly Stratford Whakamaru 1 Bunnythorpe Export South of Taranaki Haywards Twizel HVDC Benmore / Waitaki Valley Livingstone Roxburgh

27 Constraint Export South of Taranaki 220kV 110kV Taranaki Generation SFD SFD HWA BRK WVY WNG BPE BPE

28 Constraint 1 Export South of Taranaki 220kV 110kV Taranaki Generation SFD SFD HWA BRK WVY WNG BPE BPE

29 Mitigation 1 - Hawera Reactor 220kV 110kV Taranaki Generation SFD SFD HWA BRK WVY WNG BPE BPE

30 Mitigation 1 - Hawera Reactor 220kV 110kV Taranaki Generation SFD SFD HWA BRK WVY WNG BPE BPE

31 Mitigation 2 - Hawera Auto Bus Splitting Scheme 220kV 110kV Taranaki Generation SFD BRK SFD HWA WVY WNG Post Contingency Action BPE BPE

32 South Transfer Power System Limits Otahuhu Huntly Stratford Whakamaru Bunnythorpe 2 Haywards Transfer from BPE to HAY Twizel HVDC Benmore / Waitaki Valley Livingstone Roxburgh

33 Constraint 2 BPE to HAY Transfer South Flow Situation 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

34 Constraint 2 BPE to HAY Transfer South Flow Situation 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

35 Constraint 2 BPE to HAY Transfer 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

36 BPE_WDV Special Protection Scheme South Flow Situation 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

37 BPE_WDV Special Protection Scheme 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

38 BPE_WDV Special Protection Scheme South Flow Situation 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

39 BPE_WDV Special Protection Scheme South Flow Situation 220kV 110kV G TAP WDV BPE BPE MGM WIL WIL MST HAY HAY

40 Work for BPE WDV inter trip Static power flow analysis complete Project is financially approved Design stage has started 40

41 Constraints for Wellington constraints made for HVDC south BPE WDV 1&2 summer 15 min constraint 1.05 * BPE_WDV * BPE_WDV2.1 <= 54 MW Permanent stability constraint made for HVDC south WELLINGTON_STABILITY_P_1 BPE_HAY1.1 + BPE_HAY2.1 - HAY_LTN1.1 + BPE_WIL1.2 - MGM_WDV1.1 <= 1047 MW MGM_MST_1_or_MGM_WDV_1_WELLINGTON_STABILITY_O_1A BPE_HAY1.1 + BPE_HAY2.1 - HAY_LTN1.1 + BPE_WIL1.2 <= 927 MW

42 South Transfer Power System Limits Otahuhu Huntly Stratford Whakamaru Bunnythorpe Twizel HVDC Haywards 3 Benmore / Waitaki Valley Transfer Limit over HVDC 666MW Livingstone Roxburgh

43 South Island Reserve Limits Maximum HVDC south transfer = 666 MW ( Currently limited to 400 MW due to electrode line related work ) There is sufficient SIR (sustained reserve) The limitation is on FIR (fast reserve) 43

44 44 FIR is used to arrest the fall of frequency

45 DCS Transfer sent (MW) South Island FIR limitations Under Frequency Reserves for DCS A B C D E Required FIR (MW) 45

46 DCS Transfer (MW) SPD / RMT oscillation DCS scheduled Constraint Limit :00 00:30 01:00 01:30 02:00 02:30 03:00 03:30 Schedule solve time 46

47 North Island over frequency Loss of the HVDC in South Transfer can cause frequency to go over 52 Hz Limit is typically 580 MW DCS transfer (over frequency arming in service) The limit can go down to 460 MW, unusual circumstances Work is starting to increase this level. Accurate Generator governor modelling is crucial 47

48 South Transfer Power System Limits Otahuhu Huntly Stratford Whakamaru Bunnythorpe Twizel HVDC Haywards Benmore / Waitaki Valley Livingstone 4 Roxburgh Transfer into Southland

49 Constraint 4 Transfer into Southland TWZ OHB OHC BEN ISL AVI WTK CYD LIV ROX

50 Constraint 4 Transfer into Southland TWZ During Day OHB OHC ISL BEN AVI WTK CYD LIV ROX

51 Mitigation Aviemore Benmore 220kV Temporary Split TWZ OHB OHC BEN ISL AVI WTK CYD LIV ROX

52 Constraint 4 Transfer into Southland TWZ During Night OHB OHC ISL BEN AVI WTK CYD LIV ROX

53 Mitigation Islington Livingstone split TWZ During Night OHB OHC ISL BEN AVI WTK CYD LIV ROX

54 Constraint 4 Transfer into Southland TWZ OHB OHC BEN ISL AVI WTK CYD LIV ROX

55 Mitigation - Southland Special Protection Scheme TWZ OHB OHC BEN ISL AVI CYD WTK LIV ROX INV TWI

56 Mitigation - Southland Special Protection Scheme TWZ OHB OHC BEN ISL AVI CYD WTK LIV ROX INV TWI

57 Work for Southland Intertrip Static power flow analysis done Check equipment is all in place on going Dynamic power flow analysis on going Check SCADA modelling on going Test scheme Provide operational guidelines Requires customer agreement 57

58 TWZ OHB OHC BEN AVI ROX CYD WTK LIV NSY TMH INV Southland

59 Constraints for Southland constraints made for low Southland generation CYD_ROX summer 15 min constraint Permanent stability constraint made SOUTHLAND_STABILITY_P_1 CYD_ROX1.1 + CYD_ROX2.1 - INV_T1 - NMA_TMH1.1 - NMA_TMH2.1 <=?? MW

60 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 60

61 Implementing Mitigation Options Under the Code Part 12 based on a set grid configuration Prescribed circumstances for deviating from set grid Recent legal advice to the EA suggests no clear path under Code for temporary reconfigurations (on basis of net benefit) Transpower supports Code change to improve clarity and transparency Proposed Code change Provides Transpower another avenue for making deviations from set grid (permissive). Net benefit to be pre-assessed by Transpower. Circumstances to be published.

62 Further areas of work Continue to work with Authority on Code change proposal Define circumstances Calculate net benefit Consider how the market will be notified Permanent Code change proposal later in 2012, including consultation

63 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 63

64 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat FINISH 64

65 Agenda Item Introduction What is Security of Supply? Market Behaviour Enabling Increased Flows Rule Changes Outages Frequency Keeping Band FINISH Presenter Kieran Devine Shane Tennett Kevin Duckworth Lynette Bell / Mike Phethean Phyllida Crawford Stephen Cowlishaw Darren Pat 65