White Paper on the Future of Congestion Management

1. White Paper on the Future of Congestion Management IDC Granularity Task Force Standing Committee Meetings July 20-22, 2004

2. Special Thanks to… • Pat Shanahan – ATC • Alan Mok – Cinergy • Ryan Prejean – EES • Dave Robitaille – IMO • Julie Novacek – MISO • Dave Mabry – PJM • Paul Graves – Progress Energy Florida • Lanny Nickell – SPP • Rick Stegehuis – WE Energies • Bob Cummings – NERC

3. Background • June 2000 - IDCGTF formed by the SCS (now ORS) to investigate and propose technical solutions to existing inaccuracies in the IDC • June 2002 - ORS endorsed moving toward full granularity in the IDC • October 2002 - ORS provided further direction on combination of every generator to load and electrically cohesive zone methods • February 3, 2004 - RCWG requested white paper on congestion management be prepared

4. How the IDC Works Today • IDC calculates CA to CA Transaction Distribution Factors (TDFs) • A CA to CA TDF represents the impact of increasing generation in one control area and decreasing generation in another • TDFs are calculated using on-line generation • Impact of a tagged transaction on a flowgate is determined by the TDF associated with the Source CA and Sink CA • IDC CO 114 incorporate more TDF granularity for the MISO/PJM footprints

5. Problem Statement • IDC does not correctly recognize ultimate source/sink impacts of tagged transactions • IDC does not adequately address market dispatch of evolving balancing areas • TLR takes at least 30 mins to implement • Industry needs consistent and global application of granularity

6. Options Developed • IDCGTF developed three options for consideration • Options vary in complexity, paradigm shift, difficulty and timeliness of implementation • May implement all three in phases or any one or more on a standalone basis

7. Options Developed - Summary • Option 1 • increases impact calculation granularity by incorporating TP zones • relief responsibilities assigned per existing methods • relief achieved per existing methods • Option 2 • relief responsibilities assigned to BAs based on distributed impacts of a BA’s net interchange • relief achieved through transaction curtailment and/or redispatch, uses increased impact calculation granularity of Option 1

8. Options Developed - Summary • Option 3 • relief responsibilities assigned to BAs based on distributed impacts of a BA’s net interchange • relief achieved through most effective/efficient re-dispatch, uses ultimate granularity

9. Option 1 - Zones Modeled in IDC • Used by TPs in their service evaluation • Must be properly linked to tagged source/sinks • Generation zones must contain one or more generators • Load zones must contain meter-able load pockets • Zone participation factors and generation block loading order must be provided • CAs may contain one or more zones • Zones may not cross CA boundaries

10. Option 1 - Zones Modeled in IDC • FERC to provide regulatory review of TP zones • NERC to provide reliability review of TP zones • Verify that sources/sinks on the schedule match those identified on the reservation • Verify that sources/sinks on the schedule can be dispatched as scheduled • Ensure that source/sink generators associated with curtailed schedules will be re-dispatched • CA modeling remains for purposes of NNL calcs • Will use block loading order data submitted to determine a more accurate NNL dispatch

11. Option 1 - Tagging Changes • TPs required to register OASIS sources/sinks • OASIS sources/sinks will be mapped to IDC zones and tagging sources/sinks • TP responsible for those sources/sinks within their transmission footprint

12. Option 1 - Pros • Doesn’t require extensive IDC changes • Improves impact calculation granularity • Can be implemented quickly • FERC ensures comparability • Granularity used for estimating schedule impacts same as that used for provision of transmission service • Process is manageable

13. Option 1 - Cons • May not be uniform for all TP ATC/AFC methodologies • Perpetuates the myth of contract path flow-ability • Doesn’t incorporate counter-flows

14. Option 1 - Data Requirements • Block loading merit order and participation factors for all generation zones • OASIS sources/sinks registered by TPs • IDC model changes as necessary • IDC software changes • Eventual incorporation of real-time data

15. External / Internal Relief Responsibility • Applicable to both Options 2 and 3

16. IRR/ERR Calculations • IRR = Internal Relief Responsibility • IRR – calculated like NNL is calculated today • GLDFs down to zero percent used • Specific generators supporting transactions removed • Contribution based on real-time and projected data (generators and area load)

17. IRR/ERR Calculations • ERR = External Relief Responsibility • ERR – captures transactional impacts of a balancing authority’s net interchange distributed across interconnection • For exporters: ERR ~ (GSFwba minus LSFw) * Net Interchange • For importers: ERR ~ (GSFw minus LSFwba) * Net Interchange • Will need to deal with over-counting ERRs

18. CA “A” Load = 1000 MW Gen = 1100 MW Export = 100 MW GSF = 9% LSF = -9% CA “B” Load = 600 MW Gen = 200 MW Import = 400 MW GSF = -8% LSF = 10% CA “A” ERR = (GSFA – LSFWTAVG) * ExportA ERR = (.09 + .10) * 100 = 19 MWs CA “B”ERR = (GSFWTAVG – LSFB) * ImportB ERR = (.098 + .10) * 400 = 79 MWs CA “C”ERR = (GSFC – LSFWTAVG) * ExportC ERR = (.10 + .10) * 300 = 60 MWs 186 MVA CA “C” Load = 400 MW Gen = 700 MW Export = 300 MW GSF = 10% LSF = -6% FlowgateLimit 150 MVA Example ERR Calculation

19. Option 2 • Uses zonal impact calculation granularity introduced in Option 1 • Uses External/Internal relief responsibility (ERR/IRR) methodology to assign responsibilities to balancing authorities • Fulfillment of relief responsibilities accomplished through curtailment of tagged transactions and/or redispatch

20. Option 2 • First determines ERR for each area based on untagged net interchange • BAs with untagged ERR must curtail • If sufficient relief is obtained, no further action • Uses tagged interchange to determine ERR at each priority level • IRRs determined at appropriate level • BAs may fulfill ERRs through curtailment of tagged transactions and/or redispatch

21. Option 2 - Pros • IDC curtailment algorithm stays the same • Introduces improved granularity both in determination of relief responsibility and through usage of TP zones in transaction impact calculation • Adds the option of generation re-dispatch to meet the ERR based on tariff requirements • Complements CO 114 impact calculation methodology

22. Option 2 - Cons • ERRs for remote BAs could result • May be differences between ERRs assigned and relief obtained through transaction curtailments • Perpetuates the myth of contract path flow-ability • May increase complexity of coordination due to lack of curtailment prescription • May result in untimely results

23. Option 2 - Data Requirements • Block loading merit order and participation factors for all generation zones • OASIS sources/sinks registered by TPs • IDC model changes as necessary • IDC software changes • Real-time and projected output for all generators • Real-time and projected demand for each BA

24. Option 3 • Uses ERR/IRR methodology for assigning relief responsibilities • Relief achieved through re-dispatch prescribed by RCs • Provider of re-dispatch compensated through a settlement process that would charge BAs based on their relief responsibilities

25. Option 3 • Each BA will determine and document how it allocates re-dispatch costs to PtP and NITS customers • Resource availability and bid prices will be made available to RCs • Re-dispatch could take many forms • Unit pairs within same BA • Unit sales/purchases across BAs • Multiple units across multiple flowgates • Voluntary load curtailments

26. Option 3 - Issues • Re-dispatch would take place regardless of priority of transactions impacting constraint • Regulatory requirements • Responsibility for relief is transferred from PSEs to net importing/exporting BAs

27. Option 3 - Pros • Reduces amount of transactions curtailed • Improves effectiveness of relief • Relief is obtained quickly • More cost effective relief solutions • More likely to minimize potential impact on other flowgates • Can provide useful market signals

28. Option 3 - Cons • Major paradigm shift • Requires NERC commitment to address policy and regulatory issues • Requires sophisticated tools • BAs need to agree on settlement process

29. Option 3 - Data Requirements • IDC software changes • Real-time and projected output for all generators • Bid information for generators • Real-time and projected demand for each BA • Real-time telemetry, or state-estimated values, of all flowgates and OTDF flows • SDX data to include quick-start, min run times, min and max generator output, etc.

30. Recommendations to RCWG / ORS • Adopt and implement Option 1 immediately • Adopt and implement Option 3 as the long-term strategy for the IDC • Form appropriate team(s) to develop business case for implementation of these options

31. RCWG / ORS Resolution • Accept Option 1 — Implement by June 1, 2005 • Coordinate with NAESB • For Option 3 long-term solution further work—Ask the MC and IDCWG to develop by September 2005: • Functional design specification • Business case for congestion management tools • Coordinate with NAESB