White Paper on the Future of Congestion Management

IDC Granularity Task Force

Standing Committee Meetings

July 20-22, 2004

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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External / Internal Relief Responsibility

● Applicable to both Options 2 and 3

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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)

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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

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Example ERR Calculation

CA “A”Load = 1000 MWGen = 1100 MWExport = 100 MW

GSF = 9%LSF = -9%

CA “B”Load = 600 MWGen = 200 MW

Import = 400 MWGSF = -8%LSF = 10%

FlowgateLimit 150 MVA

186 MVA

CA “C”Load = 400 MWGen = 700 MW

Export = 300 MWGSF = 10%LSF = -6%

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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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.

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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

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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