Transcript ERCOT Wholesale Settlement Module 3 1
ERCOT Wholesale Settlement
Module 3
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Introduction
Can you tell these apart? BENA iq = 1 * (Σ (RI iz + LI iz + URC iz + MISD iz + MISR iz ) z + TCRPAY Bei + Σ CSC Bei ) * LRS iq
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Topics
Definitions
Settlement Overview
Settlement Calculations
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Key Definitions
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Definitions
Operating Day -
Date of power flow
Settlements-
Process used to resolve financial obligations; Assess administrative and miscellaneous fees; Provide transmission-billing determinants
Settlement Statement-
A statement issued by ERCOT reflecting a breakdown of market charges
Settlement Invoice-
A notice for payment or credit due rendered by ERCOT 5
Definitions
Initial Statement-
Posted 10 days after Operating Day
Final Statement-
Posted 59 days after Operating Day
True Up Statement-
Posted 6 months after Operating Day
Resettlement Statement-
Ad Hoc; posted as needed 6
Definitions
Charge Type-
Line item on settlement statement
Settlement Interval-
A period of time for which market services are settled
Bill Determinants-
Variables used to calculate a Charge Type 7
Definitions
Recorder -
A sequence of alpha-numeric values to identify data Example: NMLEIOL_H04_99_MYRESOURCEID,1
Channel -
Indicates the iteration of the settlement run (Initial, Final, True-Up, Resettlement) 8
Overview
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Electricity sellers
Resources
Bilateral transactions
Electricity buyers
Load Serving Entities QSEs
Bilateral transactions
$ $
QSEs Overview
ERCOT SETTLEMENTS
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“VISA Bill” Rule
All cash flow defined from ERCOT perspective:
NEGATIVE amounts
ERCOT pays Market Participant
POSITIVE amounts
Market Participant pays ERCOT
Overview
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Market Participants’ Roles
QSE:
Daily review of Settlement Statements Download of Data Extracts Shadow Settlement and Validation Research Discrepancies Register Disputes Weekly review of Invoices Settle with ERCOT
Overview
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Market Participants’ Roles
LSE / Resources:
Download of Data Extracts Research Discrepancies Settle with QSE
Overview
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Overview ERCOT's Roles
ERCOT’s Daily Settlement Procedures:
Validate Settlement Statements for publishing Create and publish Invoices (Weekly) Facilitate Invoice Payment Processes (Weekly) Participate in UFE Analysis Dispute Research and Resolution Provide Settlement information (ERCOT, PUCT, Market Participants) 14
Questions
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Settlement Calculations
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Settlement Calculations ERCOT MUST REMAIN REVENUE NEUTRAL!
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Settlement Calculations
Revenue Neutrality
All payments for Market Services will have a corresponding cost allocation.
Common forms of cost allocation Obligation Direct Assignment Load Allocation BENA Charge types are grouped into payments and cost recovery for market services.
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Settlement of What?
Settlement Calculations
ERCOT settles for services procured to manage the Texas power grid.
Capacity Settlement Energy Settlement 19
Capacity Settlement
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Learning Objectives:
Ancillary Services Replacement Reserve OOMC
Capacity Settlement
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Capacity Settlement
Ancillary Services
QSE’s AS obligation quantity based on its Load Ratio Share (LRS) QSE’s have opportunity to self-arrange their obligation ERCOT will procure at Market Clearing Price all AS obligations not self-arranged.
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Emergency Short Supply Capacity Ancillary Services Capacity
Capacity Settlement
Ancillary Services
$ $
E R C O T
$
Obligation per Load Ratio Share Self Arrangement (reduces obligation) 23
Capacity Settlement Ancillary Service Example Calculation QSE
1 2 3 Total
Obligation (MW)
500 300 200 1000
Self Arranged (MW)
250 300 0 550
Amount Short (MW)
250 0 200 450
Bid Amount (MW)
100 100 400 600
Bid Price Procurement ($/MW)
15 12 10 12
(MW)
0 50 400 450
QSE
1 2 3 Total
Payment ($)
0 -600 -4800 -5400
Allocation ($)
3000 0 2400 5400 24
Capacity Settlement Procured Ancillary Service Capacity
PC ASqi = -1 * (C ASqi * MCPC ASi )
Terms
PC : Ancillary Service Capacity Payment C: Capacity Procured MCPC: Market Clearing Price for Capacity
Subscripts
i: Interval q: QSE
Protocol 6.8.1.2
Translation: The payment for Ancillary Service Capacity is equal to the Amount of Capacity procured times the Clearing price for that Service.
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Capacity Settlement Ancillary Service Cost Allocation
LA
ASqi
= ASP
i
* NTO
ASqi Terms
LA: Load Allocated Ancillary Service Charge ASP: Ancillary Service Price NTO: Ancillary Service Net Obligation per QSE
Subscripts
i: Interval q: QSE
Protocol 6.9.1
Translation: The Load Allocation Charge for an ancillary service is equal to the Ancillary Service Price times the Net Obligation for the QSE.
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Learning Objectives:
Ancillary Services Replacement Reserve OOMC
Capacity Settlement
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Capacity Settlement
Providers of Replacement Reserve (RPRS) are paid for three distinct types of service:
Capacity Insufficiency Zonal Congestion Local Congestion 28
Section 6.8.1.10 and 6.8.1.11
Capacity Settlement
Units selected for Capacity Insufficiency or Zonal Replacement are paid:
the higher of their bid or, the highest MCPC for all Replacement Reserve procured during the procurement processes.
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Section 6.8.1.10 and 6.8.1.11
Capacity Settlement
Units selected for Local Replacement are paid:
Resource Category Generic Startup Cost for starting Resource Category Minimum Energy Cost minus MCPE for operating at the LSL.
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Section 6.8.1.10 and 6.8.1.11
Capacity Settlement
Payment from the Market is collected through the following charges:
RPRS Zonal Congestion Charge RPRS Uplift Charge 31
Section 6.9.2.1.1
Capacity Settlement
RPRS Zonal Congestion Charge
RPRS Zonal Congestion costs will be directly allocated to QSEs whose schedules have an impact on a congested Commercially Significant Constraint Note that clearing RPRS for Zonal Congestion creates shadow prices for capacity and triggers corresponding TCR payments.
Section 7.3.4.2
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Capacity Settlement
RPRS Uplift Charge ERCOT nets: The total payments for Zonal, Local and Capacity Insufficiency RPRS and The direct assigned Congestion impact and TCR Payments The difference is uplifted at Load Ratio Share to all QSEs.
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Section 6.9.2.1.2
Zonal Congestion Impact Section 6.9.2.1.2
RPRS Uplift Charge Local Replacement Capacity Settlement Zonal Replacement TCR Payments Capacity Insufficiency
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Capacity Settlement
RPRS Uplift Charge
UC RP = -1 * [ Σ ( PC RP + LPC RP ) + TCRPAY RP + Σ CSC RP ]* LRS Variables UC = RPRS Uplift Charge PC = Cost of Capacity for Zonal Congestion and Capacity Insufficiency LPC = Cost of RPRS for Local Congestion US = RPRS Under Scheduled Charge TRCRPAY = TCR Payment per Hour CSC = RPRS CSC Impact Capacity Charge LRS = Load Ratio Share
Section 6.9.2.1.2
Subscripts RP = Replacement Reserve 35
Learning Objectives:
Ancillary Services Replacement Reserve OOMC
Capacity Settlement
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Capacity Settlement
What is OOMC?
OOMC
Replacement Reserve procured out of merit order Looks a lot like Local Replacement Reserve ERCOT-wide cost is uplifted to QSEs (LRS) 37
Capacity Settlement
Units selected for OOMC are paid:
Resource Category Generic Startup Cost minus energy revenue during ramp (back 12 intervals), plus Resource Category Minimum Energy Cost minus MCPE for operating at the LSL or Replacement Bid, if cheaper.
Section 6.8.1.10 and 6.8.1.11
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Energy Settlement
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Balancing Energy
Energy Settlement
Represents the increase or decrease in energy dispatched by Settlement Interval in Real Time to ensure the balancing needs of ERCOT. The energy is supplied by ERCOT through acquisition of resources (generating units and interruptible demands) to meet load variations not covered by Regulation Service.
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Balancing Energy
Energy Settlement
Zonal Instructed Deviation (up/down) from ERCOT to QSE Used to solve power balance and/or congestion Settled at zonal MCPE How is this paid?
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Resource Imbalance
Energy Settlement
Scheduled Generation - Metered Generation Paid/charged at MCPE Why an imbalance?
Instructed Deviations Uninstructed Deviations (may be subject to URC)
Protocol 6.8.1.13
Do all Resource Imbalances result in payments to the QSE?
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Energy Settlement
Resource Imbalance Example
Situation: SQSE has scheduled to generate at 208 MW from their resource in the South Zone for IE 1630.
Conditions:
The Resource actually generates at 220MW.
The Market Clearing Price for Energy, South CM Zone is $17.09/MWh
SQSE
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220MW 208MW Energy Settlement
Resource Imbalance Example
Actual Generation Scheduled Generation
55MWh 52MWh
SQSE
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0
Energy Settlement
Resource Imbalance Example
For a given interval and zone,
RI
= (Scheduled Generation – Actual Generation) * MCPE Therefore, for interval 1630, SQSE’s Resource Imbalance in the South Zone is
RI
= (52MWh - 55MWh) * $17.09/MWh =
- $51.57
SQSE
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Energy Settlement
Resource Imbalance RI
izq
= (QRS izq - MR izq ) * MCPE iz
Terms
RI : Resource Imbalance Amount QRS: Scheduled Resource MR: Metered Resource MCPE: Market Clearing Price for Energy
Subscripts
i: Interval z: Zone q: QSE
Protocol 6.8.1.13
Translation: Resource Imbalance is the difference between the Scheduled and Actual Resource output times the Clearing Price for Energy.
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Energy Settlement
Load Imbalance
Scheduled Load - Adjusted Metered Load Paid/charged at MCPE Why an Imbalance?
UFE Forecast Inaccuracies Relaxed Balanced Schedule (section 4.3.1) LaaR’s
Protocol 6.9.5.2
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Energy Settlement
Load Imbalance Example
Situation: SQSE schedules 140 MW (35 MWh / interval) of Load in the South Zone for IE 1630
Conditions:
Adjusted Metered Load = 160 MW (40 MWh / interval) in the South Zone.
Market Clearing Price for Energy = $17.09/MWh in the South
SQSE
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160 140 Energy Settlement
Load Imbalance Example
South Zone
Actual Load Scheduled Load
35MWh 40MWh
0 SQSE
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Energy Settlement
Load Imbalance Example
For a given interval and zone,
LI
= -1*(Scheduled Load – Actual Load) * MCPE Therefore, for interval 1630, SQSE’s Load Imbalance in the South Zone is
LI
= -1*(35MWh - 40MWh) * $17.09/MWh =
$85.45
SQSE
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208 200 Energy Settlement
Load Imbalance Example
North Zone
Scheduled Load Actual Load
52MWh 50MWh
SQSE
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0
Energy Settlement
Load Imbalance Example
For a given interval and zone,
LI
= -1*(Scheduled Load – Actual Load) * MCPE Therefore, for interval 1630, SQSE’s Load Imbalance in the North Zone is
LI
= -1*(52MWh - 50MWh) * $17.09/MWh = -
$34.18
SQSE
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Energy Settlement
Load Imbalance LI
izq
= -1 * (SL izq - AML izq ) * MCPE iz
Terms
LI : Load Imbalance Amount SL: Scheduled Load AML: Adjusted Metered Load MCPE: Market Clearing Price for Energy
Subscripts
i: Interval z: Zone q: QSE
Protocol 6.9.5.2
Translation: Load Imbalance is the difference between the Scheduled and Actual Load times the Clearing Price for Energy.
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Energy Settlement
OOME
What is OOME?
Out of merit order, unit-specific energy deployment Procured by ERCOT when no market solution Paid according to a generic cost structure (Protocol Section 6.8.1.1) ERCOT-wide cost is uplifted to QSEs based on Load Ratio-Share (LRS) 58
Energy Settlement
OOME
OOME Payment Methodology
The OOME Up and OOME Down payments are intended to cover only the amount above the billable quantity times MCPE. MCPE times billable quantity is paid in Resource Imbalance. If the calculated OOM Up payment is insufficient -- additional verifiable costs may be paid if submitted in a timely manner. 59
Energy Settlement
OOME Example
Situation: SQSE receives an OOME instruction for IE 1600 to move the output of Unit 1 to 150 MW
Data for SQSE for IE 1600:
RP_Unit1 = 100 MW (25 MWh per 15 minute interval) Metered Generation by Unit1 = 36 MWh Instructed Output Level= 150MW (37.5 MWh per interval) Unit 1 is a Gas-Steam Reheat Boiler unit Generic Cost (Per Protocol 6.8.2.1) = $61.41 per MWh MCPE = $15.80 per MWh
SQSE
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Energy Settlement
OOME Example
150 144 100 Instructed Output Metered Output Resource Plan and Generation Schedule
37.5MWh
36MWh 25MWh
SQSE
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0
Energy Settlement
OOME Example
As with all settlement equations,
OOME Payment
=
-1 * Quantity * Price
Price is fairly easy:
Price
= (Generic Cost – MCPE) or 0, whichever is greater.
In this example,
Price
= $61.41- 15.80 =
$45.61 per MWh
Why do we subtract the MCPE from the Generic Cost?
SQSE
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Energy Settlement
OOME Example
Quantity is a little more difficult:
Quantity
=
The change in energy output in response to the instruction with a maximum of the instruction itself.
SQSE
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Energy Settlement
OOME Example
The unit’s response = Metered Output – Resource Plan = 36 MWh – 25 MWh = 11 MWh The unit’s instruction = Instructed Output – Resource Plan = 37.5 MWh – 25 MWh = 12.5 MWh Since the response does not exceed the instruction, ERCOT will pay SQSE for the unit’s response of 11 MWh.
SQSE
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OOME Example
Putting it all together,
OOME Payment
=
-1 * Quantity * Price
= -1 * 11 MWh * $45.61/MWh =
-$501.71
Energy Settlement SQSE
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Energy Settlement
OOME
PE OOMUPiuq = -1 * E OOMUPiuq * Max [(RCGFC c – MCPE iz ),0] Terms
PE: Price paid for OOM Energy E: Amount of OOME Energy Provided RCGFC: Resource Category Generic Fuel Cost MCPE: Market Clearing Price for Energy
Subscripts
i: Interval z: Zone q: QSE c: resource category u: generation unit
Translation: The OOM Energy premium payment is equal to the Energy provided times the difference between MCPE and the Generic cost for the OOME service.
Protocol 6.8.2.3
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Energy Settlement
OOME
PE OOMUPiuq = -1 * E OOMUPiuq * [Max (RCGFC c – MCPE iz ),0]
where
E OOMUPiuq = Max (0, Min ((MR iuq – OL iuq ), I OOMUPiuq )) Terms:
MR = Metered Resource OL = Resource Plan Output Level I = OOME Instruction
Subscripts
i: Interval z: Zone q: QSE c: resource category u: generation unit
Protocol 6.8.2.3
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Uninstructed Resource Charge Uninstructed Resource Charge (URC)
A QSE who schedules resources will be paid the full Market Clearing Price for Energy Up to the amount of instructed deviations An Uninstructed Deviation Charge Back will be calculated at a factor of the MCPE. The Uninstructed Deviation Charge Back will be applied to each Congestion Zone in which a QSE has a deviation from schedule plus instructions.
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Integrated Amount of ERCOT Regulation is less than -25 MWhrs
Price Chasing
Uninstructed Resource Charge Metered Resource is greater than larger of 101.5% of (or 5MWh over) total schedule plus Instruction
Uncontrollable Renewable Resource has generated more than 150% of its Schedule
Over Generation in a zone where MCPE is positive Uninstructed Resource Charge
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Integrated Amount of ERCOT Regulation is greater than 25 MWhrs Uninstructed Resource Charge
Cost Optimization
Metered Resource is less than lesser of 98.5% of (or 5MWh under) total schedule plus Instruction
Uncontrollable Renewable Resource generates less than 50% of Schedule.
Under Generation in a zone where MCPE is negative Uninstructed Resource Charge
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Congestion Management - Zonal
Settlement of Zonal Congestion
QSE impact is determined by the bilateral schedule The net Resource schedule (Resource – Obligation) for each zone is multiplied by the zonal shift factor for each Commercially Significant Constraint (CSC).
The CSC impacts are added together The QSE is charged the Impact on the CSC multiplied by the Shadow Price on the CSC.
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Congestion Management - Zonal Congestion Management Example West to North CSC West Zone North Zone South to West CSC South Zone South to North CSC
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Congestion Management - Zonal Shift Factors CSC Zonal Average Weighted Shift Factors CM Zone names
Average Weighted Shift Factor
West to North
Average Weighted Shift Factor
South to North
Average Weighted Shift Factor
South to West West2004 North2004 South2004 0.489911548
-0.008056712
0.002302236
-0.004425342
-0.120276952
0.503257831
-0.016725781
-0.003225342
0.104328870
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Congestion Management - Zonal Where do you find the real shift factors?
https:tcr.ercot.com
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Congestion Management - Zonal Congestion Management Example
Situation: SQSE schedules 548 MW of Resource from the South Zone and delivers 140 MW to the South Zone and 408 MW to the North Zone.
The South to North congestion Path is constrained.
MCPE_North = $28.84
MCPE_South = $17.09
MCPESPC_SN = $32.91
SQSE
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West Congestion Management - Zonal Congestion Management Example North Res = 0MW Load = 408MW South Res = 548MW Load = 140MW SQSE
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Congestion Management - Zonal Congestion Management Example
SQSE’s South Zone Schedule impacts the South to North constraint as follows:
Impact
= (Resource – Obligation)(1/4 hr) * SF SN = (548 MW – 140MW)(1/4 hr) * 0.503257831
=
51.33 MWh
SQSE’s North Zone Schedule impacts the South to North constraint as follows:
Impact
= (Resource – Obligation)(1/4 hr) * SF SN = (0 MW – 408MW)(1/4 hr) * -0.120276952
=
12.27 MWh SQSE
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Congestion Management - Zonal Congestion Management Example
Now the Congestion Charge for a particular CSC is simply a quantity times a price:
Congestion Charge
= (Sum of Impacts) * Shadow Price = (51.33 MWh + 12.27 MWh)($32.91/MWh) =
$2093.08
SQSE
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Congestion Management - Zonal CSC Schedule Impact I CSCiq = Σ((QSS iqz – SO iqz ) * SF ZCSC ) z Terms
I: Scheduled MW Impact per CSC QSS: QSE Supply Schedule SO: Scheduled Obligation SF: Shift Factor
Subscripts
i: Interval q: QSE z: zone CSC: Commercially Significant Constraint
Protocol 7.3.4.1
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Congestion Management - Zonal Congestion: CSC Impact CSC BECSCiq = SPC CSCi * MAX(0, I CSCiq ) Terms
I: Scheduled MW Impact per CSC CSC BE : Energy Related Congestion Charge SPC: Shadow Price
Subscripts
i: Interval q: QSE CSC: Commercially Significant Constraint What happens if my impact is negative?
Protocol 7.3.4.1
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Congestion Management - Zonal Congestion: CSC Counterflow CSC BECSCiq = SPC CSCi * I CSCiq Terms
I: Scheduled MW Impact per CSC CSC BE : Energy Related Congestion Charge SPC: Shadow Price
Subscripts
i: Interval q: QSE CSC: Commercially Significant Constraint
Protocol 7.3.4.1
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Congestion Management - Zonal Congestion Management – TCR Example
Situation: If SQSE had bid for and purchased 100 TCRs for this month at $3 a piece, then the impact is as follows: Cost of TCRs = 100 * $3 = $300 (covers entire month) Cost of congestion from IE 1630 = $2,093.08 Payment from TCR = TCR/4 * MCPESPC_SN = (100/4) * $32.91 = $822.75
SQSE cost for Congestion = $2,093.08 – $822.75 = $1270.33
(minus the monthly amortized cost of the TCR) SQSE
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100 MW
Congestion Management - Local OVERLOAD
200 MW Limit = 500 MW 300 MW 200 MW “Generate at 200” Question: How does ERCOT select the unit?
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Congestion Management - Local Congestion Management – Unit Selection
In real time, ERCOT manages Local Congestion using unit specific deployments.
Units selected are paid by their Bid Premiums if a Market Solution is used.
Units selected are paid as OOM if no Market Solution exists.
Charge uplifted to QSEs on a Load Ratio Share Basis.
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Energy Settlement
Mismatched Schedules
What happens if the following schedule is not resolved?
QSE A QSE B R QSE A 100MW (South) O R 100MW QSE B (South) QSE A 120MW Mismatch (South) O 120MW QSE B (South)
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Energy Settlement
Mismatched Schedules
QSE A QSE B R QSE A 100MW (South) O R 100MW QSE B (South) QSE A 120MW Mismatch (South) O 120MW QSE B (South)
Resolved in Settlement
QSE A 100MW (South) ERCOT 20MW (South)
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Energy Settlement
Mismatched Schedules
MISD iqz = -1 * MISAMTD iqz * MCPE iz MISR iqz = MISAMTR iqz * MCPE iz Terms:
MISD: Payment for mismatched amount delivered to ERCOT MISR: Charge for mismatched amount received from ERCOT MISAMTD: Mismatched amount delivered to ERCOT MISAMTR: Mismatched amount received from ERCOT MCPE: Market Clearing Price for Energy
Subscripts
i: Interval z: Zone q: QSE
Translation: The mismatch payment or charge is equal to the mismatch amount delivered to or received from ERCOT times the MCPE.
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Learning Objectives:
Balancing Energy Resource Imbalance Load Imbalance OOME Uninstructed Resource Charge Congestion Mismatched Schedules BENA
Energy Settlement
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Energy Settlement Balancing Energy Neutrality Adjustment
Resource Imbalance $ $ Mismatch Energy Delivered Load Imbalance $
B E N A
$ Mismatch Energy Received $ $ $ TCR Payments Balancing Energy CSC Charges Uninstructed Resource Charge 92
Energy Settlement Balancing Energy Neutrality Adjustment BENA iq = 1 * (Σ (RI iz + LI iz + URC iz + MISD iz + MISR iz ) z + TCRPAY Bei + Σ CSC Bei ) * LRS iq Terms
BENA: Balancing Energy Neutrality Adjustment RI: Resource Imbalance LI: Load Imbalance URC: Uninstructed Resource Charge MISD: Mismatched Energy Delivered MISR: Mismatched Energy Received TCRPAY: Transmission Congestion Right Payments CSC: Direct Assigned Congestion Cost LRS: Load Ratio Share
Protocol 9.6.1
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Energy Settlement Balancing Energy Neutrality Adjustment BENA iq = 1 * (Σ (RI iz + LI iz + URC iz + MISD iz + MISR iz ) z + TCRPAY Bei + Σ CSC Bei ) * LRS iq
Translation: The Balancing Energy Neutrality Adjustment is equal to the Sum of the Load Imbalances, Resource Imbalances, Uninstructed Resource Charges, Mismatch Charges, TCR Payments and Direct Assigned Congestion costs allocated at Load Ratio Share.
Protocol 9.6.1
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Questions
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