ercot market analysis
DESCRIPTION
Review of the Methodology for Setting Transmission Shadow Price Caps for Irresolvable Non-Competitive Constraints in SCED. ERCOT Market Analysis. References. ERCOT Business Practice “Setting the Shadow Price Caps and Power Balance Penalties in Security Constrained Economic Dispatch” - PowerPoint PPT PresentationTRANSCRIPT
ERCOT Market Analysis
Review of the Methodology for Setting Transmission Shadow Price Caps for IrresolvableNon-Competitive Constraintsin SCED
January 9, 2013
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References
• ERCOT Business Practice “Setting the Shadow Price Caps and Power Balance Penalties in Security Constrained Economic Dispatch”– The appropriate section of this document is noted in the headers of
the following slides
• ERCOT Business Practice “System-Wide Offer Cap and Scarcity Pricing Mechanism Methodology”– Contains LCAP definition
January 9, 2013
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Default Shadow Price Caps – 3.5
January 9, 2013
Constraint TypeDefault
Shadow PriceCap
Base Case $5,000
345 kV $4,500
138 kV $3,500
69 kV $2,800
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Trigger Conditions – 3.6.1
• A non-competitive constraint violation is not resolved by the SCED dispatch or overridden for more than two consecutive hours on more than 4 consecutive Operating Days; or
• A non-competitive constraint violation is not resolved by the SCED dispatch or overridden for more than a total of 20 hours in a rolling thirty day period.
January 9, 2013
Contingency Name Constraint Name Trigger Date
SCABWES8 NAVAL__N_PADR1_1 12/6/2010SNCWMOS8 ODNTH_FMR1 12/7/2010DW_DDEN8 AIR_W_DE_1 2/1/2011BASE CASE VALIMP 2/3/2011DODEQAL5 6611__A 2/28/2011SODBODN9 6860__A 3/11/2011SKEYWLV8 6611__A 3/21/2011DGRSLNC5 6856__B 6/3/2011SKEYWLV8 6611__C 6/18/2011SNCWHLT9 6915__A 6/21/2011DODEQAL5 6215__A 5/3/2012SSUNMGS8 6215__A 10/10/2012XMGS58 MGSES_MR1H 10/31/2012
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Trigger Conditions – 3.6.1
• Resource C and D identification– Resource C – used in determination of shadow price cap
• The Generation Resource with the lowest absolute value of the negative shift factor impact on the violated constraint
– Resource D – used for net margin calculation• The Generation Resource with the highest absolute value of the negative shift
factor on the violated constraint.
– Resources with < 2% abs(shift factor) are ignored• In cases for which there is no Resource C, SP cap is set to $2,000• In cases for which there is no Resource D, net margin is calculated based on
Settlement Point of the Resource with the most negative shift factor
• The day the trigger is met is used to determine Resource C and D
• For the end of year evaluation (3.6.2), the last day the constraint was binding is used
January 9, 2013
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Trigger Conditions – 3.6.1
• Resource C data for Shadow Price Caps effective January 1, 2013• For VALIMP, the Resource C shift factor was 96.3%• For other constraints in which a Resource C was identified, the shift
factors ranged between 2.0% and 3.4%
January 9, 2013
Contingency Name Constraint Name Resource Type
BASE CASE VALIMP SCLE90
DGRSLNC5 6856__B Not Applicable
DODEQAL5 6215__A WIND
DODEQAL5 6611__A WIND
DW_DDEN8 AIR_W_DE_1 HYDRO
SCABWES8 NAVAL__N_PADR1_1 CCGT90
SKEYWLV8 6611__A SCLE90
SKEYWLV8 6611__C SCLE90
SNCWHLT9 6915__A SCLE90
SNCWMOS8 ODNTH_FMR1 WIND
SODBODN9 6860__A WIND
SSUNMGS8 6215__A SCLE90
XMGS58 MGSES_MR1H WIND
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Methodology for Setting the Shadow Price Cap – 3.6.2
• The Shadow Price Cap on this constraint will initially be set to the minimum of:– The current value of the Generic Shadow Price Cap as determined
in Section 3.5, and – The Maximum of the largest value of the Mitigated Offer Cap / abs
(SF) for Generation Resource C or $2000.
January 9, 2013
$2,000 $2,800$3,500$4,500$5,000
MOC SF
$0
Range of allowed SP cap
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Current Constraints with Modified Shadow Price Caps
Constraints in RED will be reset to default values on January 17, 2013
as they have been determined to be resolvable
January 9, 2013
Contingency Name Constraint NameConstraint
Type
Maximum Shadow
Price
BASE CASE VALIMP Base Case $2,000.00
DGRSLNC5 6856__B 69 kV $2,000.00
DODEQAL5 6215__A 138 kV $2,000.00
DODEQAL5 6611__A 69 kV $2,000.00
DW_DDEN8 AIR_W_DE_1 138 kV $2,000.00
SCABWES8 NAVAL__N_PADR1_1 69 kV $2,000.00
SKEYWLV8 6611__A 69 kV $2,000.00
SKEYWLV8 6611__C 69 kV $2,473.89
SNCWHLT9 6915__A 69 kV $2,800.00
SNCWMOS8 ODNTH_FMR1 69 kV $2,000.00
SODBODN9 6860__A 69 kV $2,320.68
SSUNMGS8 6215__A 138 kV $2,000.00
XMGS58 MGSES_MR1H 345 kV $2,000.00
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Net Margin Calculation – 3.6.3
• The Settlement Point Price at the Resource Node for Generation Resource D is the net margin reference SPP.
• The constraint net margin calculation is:
∑ ¼ * MAX(0, (net margin reference SPP – 10*FIP))over all intervals in which the constraint is binding
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Net Margin Calculation – 3.6.3
• As constraint binding periods are defined by SCED interval, the SCED intervals must be converted to the appropriate Settlement Intervals for the net margin calculation
January 9, 2013
SCED Intervals (5 min)Settlement Intervals (15 min)
10:00:20 10:45:08
10:30
10:30:09
Example Calculation
10:00 11:00
Net Margin = ¼ * (SPP – 10*FIP)
CONTINGENCY_NAME CONSTR_NAME SCED_TS_START SCED_TS_END SHADOW_PRICESI_START(Intvl Ending)
SI_END(Intvl Ending)
SNCWMOS8 ODNTH_FMR1 11/4/2012 10:25:09 11/4/2012 10:30:09 $460.39 11/4/2012 10:30 11/4/2012 10:45
SNCWMOS8 ODNTH_FMR1 11/4/2012 10:30:09 11/4/2012 10:35:19 $623.96 11/4/2012 10:45 11/4/2012 10:45
SNCWMOS8 ODNTH_FMR1 11/4/2012 10:35:19 11/4/2012 10:40:10 $622.05 11/4/2012 10:45 11/4/2012 10:45
SNCWMOS8 ODNTH_FMR1 11/4/2012 10:40:10 11/4/2012 10:45:08 $598.39 11/4/2012 10:45 11/4/2012 11:00
SNCWMOS8 ODNTH_FMR1 11/4/2012 10:45:08 11/4/2012 10:50:09 $661.67 11/4/2012 11:00 11/4/2012 11:00
CONTINGENCY_NAME CONSTR_NAME STL_PNT_NAME DELIVERY_TIME SPP 10*FIP NET_MARGIN NET_MARGIN_TOTALSNCWMOS8 ODNTH_FMR1 NWF_NWF1 11/4/2012 10:30 $50.88 $32.40 $4.62 $161,964.16SNCWMOS8 ODNTH_FMR1 NWF_NWF1 11/4/2012 10:45 $96.02 $32.40 $15.91 $161,980.07SNCWMOS8 ODNTH_FMR1 NWF_NWF1 11/4/2012 11:00 $53.89 $32.40 $5.37 $161,985.44
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Net Margin Calculation – 3.6.3
• End of 2012 net margin calculations
• Totals were reset to zero on January 1, 2013
January 9, 2013
Contingency Name Constraint Name Settlement Point Effective Date Net Margin Total
SNCWMOS8 ODNTH_FMR1 NWF_NWF1 1/1/2012 $161,985.44
DODEQAL5 6215__A CSC_CSECG1_2 5/3/2012 $19,983.84
SSUNMGS8 6215__A BULLCRK_1_2 10/11/2012 $92,306.72
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• When $95,000 net margin is reached, the Shadow Price Cap on this constraint will be set to the minimum of:
– $2,000, or
– The maximum of the largest value of the Mitigated Offer Cap / abs (SF) for Generation Resource C or the current effective LCAP.
• SNCWMOS8:ODNTH_FMR1 met this condition on August 6. Its Shadow Price Cap was changed from $2,274.65 to $2,000.00.
Methodology for Setting the Shadow Price Cap – 3.6.2
• On November 7, 2012, the LCAP definition was changed frommax(50*FIP, $500) to max(50*FIP, $2,000)
January 9, 2013
$2,000 $2,800$3,500$4,500$5,000
MOC SF
$0
$95K Prior to $95K range
LCAP
• Since LCAP can never be lower than $2,000, the equation above now reduces to:When $95,000 is reached, the Shadow Price Cap will be set to $2,000
$500
range
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Methodology for Setting Transmission Shadow Price Caps or Irresolvable Non-Competitive Constraints in SCED
Questions?
January 9, 2013