December 2, 2004 Congestion Causes and Effects Presented to WMS January 14, 2005 Beth Garza

December 2, 2004 CongestionCauses and Effects

Presented to WMSJanuary 14, 2005

Beth Garza

BGarza / January 14, 2005 / WMS

2

Issue Statement

Transmission Outages on Dec 2 & 3 lowered the NE-N CSC limit to a level where TCRs became very valuable and payments to TCR holders exceeded congestion payments by over $6 M which was uplifted through BENA


3

Topics to Cover

• Day Ahead Info

• Prices

• Transmission Outages

• BENA/Uplift effects

• TCR Auction vs. Day Ahead Limit

• Pre-controlling CSC limits


4

Transmission Limits to Be MonitoredFor: Thursday 12/02/2004

The maximum total loading on the following Zonal and Local Constraint monitored elements should be maintained. Local constraints will be resolved with Real Time Contingency Analysis

Time

South to North

SDSES–TMPSW

__ Potential IROL

Northeast to North

(Sum of 2 Farmerville - Royse)

__Potential IROL

South to Houston

(Sum of 3 STP-DOW & STP-WAP)

__ Potential IROL

West to North

Graham – Parker/ Benbrook

__ Potential IROL

North to Houston

Gibbons Creek – O’BrienJewett – T.H. WhartonJewett – TomballRNS – Kuykendahl

__ Potential IROL

00:00- 06:00

840400

1660 600 2460

06:00 -12:00

840100

1660 600 1670

12:00 -23:00

840100

1660 600 1670

23:00 -24:00

840400

1660 600 2460

Northeast => North Loss of single 345 kV circuit Collin-Carrolton results in overloading of Krugerville-Denton Arco 138 kV line

Above Zonal limitations are based on the following:


5

Transmission Limits to Be MonitoredFor: Thursday 12/02/2004 REVISED[1]


Time

South to NorthSDSES–TMPSW

__ Potential IROL

Northeast to North(Sum of 2 Farmerville - Royse)__Potential IROL

South to Houston

(Sum of 3 STP-DOW & STP-WAP)__ Potential IROL

West to NorthGraham – Parker/ Benbrook__ Potential IROL

North to HoustonGibbons Creek – O’brienJewett – T.H. WhartonJewett – TomballRNS – Kuykendahl __ Potential IROL

00:00- 06:00

840400

1660 600 2460

06:00 -11:00

840100

1660 600 1670

11:00-12:00

840270

1660 600 1670

12:00 -23:00

840270

1660 600 1670

23:00 -24:00

840400

1660 600 2460

Northeast => North

Loss of single 345 kV circuit Collin-Carrilton results in overloading of Krugerville-Denton Arco 138 kV line

[1] Revision was made to reflect a change in online units from the day-ahead study.


6

MCPE by Interval Ending

-$2,500.00

-$2,000.00

-$1,500.00

-$1,000.00

-$500.00

$0.00

$500.00

$1,000.00

Interval Ending

MC

PE

($)

NORTH

SOUTH

WEST

HOUSTON

NORTHEAST

December 2, 2004


7

Interval Ending MCPE Results

02-Dec-04 NORTH SOUTH WEST HOUSTONNORTHEAST

3:15 $76.43 $14.08 $74.69 $41.15 $77.32

3:30 $86.55 $8.12 $84.37 $42.17 $87.68

3:45 $72.89 $19.33 $71.40 $42.58 $73.66

4:00 $76.93 $25.80 $75.51 $48.00 $77.67

4:15 $54.15 $30.68 $53.50 $40.87 $54.49

4:30 $51.12 $35.28 $50.68 $42.16 $51.35

4:45 $89.06 $9.07 $86.84 $43.80 $90.21

5:00 $442.54 $5.50 $369.84 $194.39 $9.10

5:15 $101.73 $2.50 -$223.75 $41.06 -$2240.71

5:30 $459.19 -$198.33 -$298.20 $46.00 -$299.00

5:45 $459.19 -$11.40 -$298.20 $73.15 -$299.00

6:00 $459.19 $35.00 -$298.20 $73.15 -$299.00

6:15 $459.19 -$20.00 -$289.00 -$872.20 -$299.00

6:30 $41.88 $41.88 $41.88 $41.88 $41.88

Balancing Energy Information for Market Day: 2-Dec-04


8

Zonal Shift Factors for NE-N CSC

The most effective combination to relieve NE-N congestion is to Balance Down in the NE / Up in the North.– 41.31% impact

West

+0.23%

North-5.51%

NE

+35.8%

South

-3.76%

Hou

-4.44%

ZoneMarginal Cost

MW deployed

Shift Factor on NE-N

MW impact Cost

Northeast 9.1 -2.42 35.80% -0.867 ($22)

North 442.54 2.42 -5.51% -0.133 1072

0 -1 $1049


9

Shadow price and Northeast MCPE calculation for December 2 / 05:15

ZoneMarginal Cost

MW deployed

Shift Factor on NE-N

MW impact Cost

Houston

41.06 107.34 -4.44% -4.766 $4407

West -223.75 -6.75 0.23% -0.016 $1510

South 2.50 -100.64 -3.76% 3.784 ($252)

North 101.73 .05 -5.51% -0.003 $ 5

0 -1 $5670 Shadow Price

Power balance is maintained while reducing flow on NE-N CSC

Once Down Balancing in the Northeast is exhausted, the system looks to other zones

MCPE for the Northeast is now determined from its relation to these costs

MCPEz – MPCE NE = SP*(SFNE – SFz)

MCPEz – SP*(SFNE – SFz) = MCPENE = $2241


10

Hour Price MW Hour Price MW Hour Price MW

7 40 270

5 14 36 6 14 36 7 14 313

5 13 71 6 13 71 7 13 356

5 12 107 6 12 107 7 12 399

5 11 143 6 11 143 7 11 441

5 10 179 6 10 179 7 10 484

5 9 214 6 9 214 7 9 527

5 8 250 6 8 250 7 8 570

5 7 278 6 7 278 7 7 592

5 6 306 6 6 306 7 6 614

5 5 333 6 5 333 7 5 637

5 4 361 6 4 361 7 4 659

5 3 389 6 3 389 7 3 681

5 2 417 6 2 417 7 2 703

5 1 444 6 1 444 7 1 726

5 0 472 6 0 472 7 0 748

5 -1 500 6 -1 500 7 -1 770

5 -299 505 6 -299 505 7 -299 775

5 -1000 505 6 -1000 505 7 -1000 775

Aggregated Balancing Energy Down BidsNortheast Zone - December 2, 2004

Hour

Generation Scheduled

MW% Offered as DBES

5 2148 – 2222 22-23%

6 2482 – 2924 17-20%

7 3388 23%


11

Key Transmission Outages

Element Requested Start End

Olinger – Ben Davis /138kV 10/13 12/1 07:0012/1 06:50

12/2 17:0012/1 17:13

Olinger – Firwheel /138kV 10/13 12/3 07:0012/3 06:50

12/4 17:0012/4 17:23

Collin SES – Bridges /138kVUpdated

11/1211/23

11/15 00:1511/20 08:03

12/3 12:0012/4 20:00

Royse Switch CB_4620Removes Royse SW – Allen SW /345kV 11/16

11/29 07:0011/29 08:55

12/12 20:0012/11 13:33

Dalrock Road – Rockwall TapRowlett Tap – RowlettRowlett Tap – RockwallRowlett Tap – Garland /138kV 11/24 12/1 18:15 12/15 19:00

Roanoke – West Denton /345kVRemoves Denton AT

11/28 12/1 06:3012/1 07:33

12/4 16:0012/4 15:50

McKinney SW – McKinney White StMcKinney SW – McKinney

11/29 12/2 06:0012/2 06:06

12/3 20:0012/3 15:17/15:05

Forney Switch – Rockwall South / 138kVCancelled

11/2912/2 05:12

12/2 06:00 12/9 19:00


12


13

OOME, LBE, OOMC, BENA, RMR

$0.00

$0.50

$1.00

$1.50

$2.00

$2.50

$3.00

$ p

er M

Wh

2004 Actual YTD 2003 Actual Daily Actual

12/2/2004 - $7.04


14

Northeast - North

12/2/04 Interval ending Limit CSCI

Shadow Price

Zonal Congestion

Charge TCRsPayment to TCR holders

Zonal Congestion

Shortfall Collected

Through BENA

3:00 9999 474.4713 0 $0.00 1851 $0.00 $0.00

3:15 9999 477.1653 0 $0.00 1851 $0.00 $0.00

3:30 9999 473.2188 0 $0.00 1851 $0.00 $0.00

3:45 9999 460.9552 0 $0.00 1851 $0.00 $0.00

4:00 9999 439.38 0 $0.00 1851 $0.00 $0.00

4:15 9999 360.0779 0 $0.00 1851 $0.00 $0.00

4:30 610 340.2008 0 $0.00 1851 $0.00 $0.00

4:45 590 336.6925 0 $0.00 1851 $0.00 $0.00

5:00 530 348.6249 1063.8 $92,716.79 1851 ($492,273.45) ($399,556.66)

5:15 530 446.2523 5670.4 $632,607.26 1851 ($2,623,977.60) ($1,991,370.34)

5:30 500 460.3259 1835.37 $211,217.09 1851 ($849,317.47) ($638,100.38)

5:45 500 463.9667 1835.37 $212,887.64 1851 ($849,317.47) ($636,429.83)

6:00 525 458.0223 1835.37 $210,160.10 1851 ($849,317.47) ($639,157.37)

6:15 650 828.7812 1835.37 $380,280.04 1851 ($849,317.47) ($469,037.43)

6:30 9999 818.6716 0 $0.00 1851 $0.00 $0.00

$1.7 million ($6.5 million) ($4.8 million)


15

Zonal Congestion

Charge($000)

Payment to TCR Holders

($000)

Zonal Congestion Shortfall Collected

Through BENA($000)

Dec 2 NE-N $1,740 ($6,514) ($4,774)

Dec 2 S-N $156 ($245) ($89)

Dec 2 Total $1,896 ($6,759) ($4,863)

Dec 3 NE-N $1,589 ($3,155) ($1,566)

Dec 3 S-N $337 ($585) ($248)

Dec 3 Total $1,926 ($3,740) ($1,814)

2 Day NE-N $3,329 ($9,669) ($6,340)

2 Day Total $3,822 ($10,499) ($6,677)

Summary of 2 Day Congestion Costs


16

Daily CSC limits vs TCRsAnnual TCRs include PCRs

0

500

1000

1500

2000

2500

1-Jul 31-Jul 30-Aug 29-Sep 29-Oct 28-Nov 28-Dec

NE-NAnnual TCRs

Daily OC0 Limit

Total TCRs

Monthly OC0


17

Possible reasons for discrepancy between the Monthly TCR calculation and the Daily CSC limits calculation

:

• Monthly TCR calculation occurs 45 days in advance– TSPs only required to submit outages 3 days in advance

• There were several line-ratings changes that occurred in November not considered in the monthly calculation

• No generator outages are considered in the monthly calculation

• No dynamic ratings are used in the monthly calculation• Operations case vs. SSWG case• Generators not adjusted individually in monthly

calculation• Overloads on lines with PTDF’s of less than 4.0% are

ignored• Settlement Adjustment consideration differences


18

December NE – N TCR Calculation with Actual Transmission Outages

Line Outages:• December TCR study included 33

line outages.• 130 line and transformer outages

actually occurred on December 2.• Using a 5-day outage criteria,

there were 67 line and transformer outages on December 2.

Variables considered:• Line Outages (All, 5-Day window)• Updated Ratings (with and without

the 11/12/2004 update)• Normally, the limiting contingency

is chosen by MUST. One case using the 5-day window outages was run using the contingency chosen by operations.

1851

364

324

401

374

827

1393

-155

-155

-120

-106

348

-500 0 500 1000 1500 2000

Original

All Outages

5 day Outages

All Outages with Update

5 day Outages with Update

Using Op Contingency 5day

Avaliable TCRs OC 0


19

Requested Days Prior Planned Start

0

500

1000

1500

2000

2500

3000

3500

3 17

31

45

59

73

87

10

1

11

5

12

9

14

3

15

7

17

1

18

5

19

9

21

3

22

7

24

1

25

5

26

9

28

3

29

7

31

1

32

5

33

9

35

3

Days Prior Outage

Transmission


20

•2.2.2 OC1 Limits for Outage Support

Step # Procedural Steps

NOTE: If step 1.2 is required, use the MIS and post that ERCOT is controlling to a limit other than the one posted.Typical Script: The “CSC Name” limit will change to “MW Amount” at “Time”. ERCOT will start controlling to this limit in accordance with Section 2.2.2 of the Transmission Security Desk procedures.

1 Adjust OC1 limits as required to support an outage.1.1 If flow across a CSC is already below the limit required to support an outage, then it is permissible to wait and adjust the OC1 limit at the scheduled start time of the outage.1.2 IF flow across a CSC is above the limit required to support an outage, then adjust the OC1 limits for intervals preceding the scheduled outage start time such that flow across the constraint is gradually reduced to at or below the limit required to support the specific outage. While this action might result in over-constraining for a brief period, it is preferable to the negative effects of a sudden reduction in the OC1 limit.

2 When a CSC limit changes, immediately change the limit in RTMONI. Record this event in the Transmission Security log.

ERCOT Operating Procedure ManualTransmission & Security Desk

Procedures

Version 3 Rev 32 – December 20, 2004 Page 11


21

Additional background slides


22

Transmission Limits to Be MonitoredFor: Wednesday 12/01/2004


Time

South to NorthSDSES–TMPSW__ Potential IROL

Northeast to North(Sum of 2 Farmerville - Royse) Potential IROL

South to Houston



North to HoustonGibbons Creek – O’BrienJewett – T.H. WhartonJewett – TomballRNS – Kuykendahl __ Potential IROL

00:00- 08:00

830520

1840 600 2200

08:00 -12:00

830520

1840 600 1900

12:00 -18:00

830520

1840 600 1900

18:00 -24:00

830520

1840 600 2200

South => North Loss of Double Austrop-Sandow 345 kV circuit overloads Austrop Auto.

Northeast => North Base case activation of an SPS (ALNSW-BNDVS) and post-contingency overload of Collin-Frisco 138 kV line on the forced outage of Carrollton-Collin 345 kV.

South => Houston Loss of Dbl STP – DOW 345kV Lines loads Blessing – Lane City.

West => North Loss of MGSES - SWCOG loads multiple underlying 69kV lines.

North=> Houston Loss of Double circuit Gibbons Creek-Twin Oak overloads Jewet-Watson Chapel



23

Transmission Limits to Be MonitoredFor: Friday 12/03/2004


Time



South to Houston




00:00- 06:00

840650

1990 600 2100

06:00 -12:00

840300

1990 600 2100

12:00 -23:00

840300

1990 600 2100

23:00 -24:00

840650

1990 600 2100

South => North Loss of Double Sandow – Temple 345kV lines overloads Sandow – Rogers 138kV Line.

Northeast => North Base case activation of NE SPS Allen Switch – Ben Davis above trigger point. Offpeak – outage of NW Carrillton-Collin overloads Krugerville-Denton Arco &

South => Houston Loss of Double Sandow – Temple 345kV lines overloads Sandow – Rogers 138kV Line.


North=> Houston Loss of Double circuit GIBBON CRK - O’BRIEN & - ROANS PRAIRIE results in overload of 345kv line Jewett –T.H. Wharton.



24

Transmission Limits to Be MonitoredFor: Saturday 12/04/2004


Time



South to Houston




00:00- 07:00

8301190

2090 600 2220

07:00 -12:00

8301190

2090 600 2150

12:00 -16:30

8301190

2090 600 2150

16:30 -24:00

8301190

2090 600 2220

South => North Loss of Double Sandow – Temple 345kV lines overloads Sandow – Rogers 138kV Line.

Northeast => North Loss of NW Carrollton-Collin 345 kV overloads Collin – Frisco 138 kV(Adjusted Forney Generation for overload of Royse – Ben Davis 345 kV)

South => Houston Loss of Dbl STP – Dow 345 kV overloads Waller – Prairie View 138 kV


North=> Houston Loss of Double circuit GIBBON CRK - O’BRIEN & - ROANS PRAIRIE results in overload of 345kv line Jewett –T.H. Wharton. (07:00 – 16:30)Loss of Dbl THW-Jewett / Obrien—Gibbons Creek 345 kV overloads Waller – Prairie View 138 kV (00:00 – 07:00 and 16:30 –24:00)



25

-350

-300

-250

-200

-150

-100

-50

0

50

100

0 100 200 300 400 500 600 700 800 900

$/M

WH

HE 5

HE 6

HE 7

Northeast DBES BidsDecember 2, 2004


26

BES Deployments by Zone

-2500

-2000

-1500

-1000

-500

0

500

1000

1500

2000

NORTH

SOUTH

WEST

HOUSTON

NORTHEAST

December 2, 2004


27

Interval Ending BES Deployments (MW)

02-Dec-04 NORTH SOUTH WEST HOUSTONNORTHEAST

3:15 222 -382 47 657 0

3:30 355 -409 47 848 0

3:45 336 -365 47 887 0

4:00 336 -340 47 943 0

4:15 309 -348 83 177 0

4:30 264 -345 95 384 0

4:45 469 -408 197 637 0

5:00 582 -479 531 1022 -215

5:15 986 -874 68 150 -501

5:30 1319 -1316 -14 579 -505

5:45 1372 -1462 -74 883 -505

6:00 1424 -974 -74 883 -505

6:15 1802 -2028 -216 -741 -675

6:30 0 -842 83 -60 -274

Balancing Energy Information for Market Day: 2-Dec-04


28

Net Balancing Energy

(2,500)

(2,000)

(1,500)

(1,000)

(500)

0

500

1,000

1,500

2,000

3:00 3:15 3:30 3:45 4:00 4:15 4:30 4:45 5:00 5:15 5:30 5:45 6:00 6:15 6:30 6:45 7:00

Net Balancing Energy DeployedDecember 2, 2004


29

South - North

12/2/04Interval ending Limit CSCI

Shadow Price

Zonal Congestion

Charge TCRsPayment to TCR holders

Zonal Congestion

shortfall collected

through BENA

3:00 9999 296.1346 0 $0.00 513 $0.00 $0.00

3:15 399 319.0686 152.07 $12,130.19 513 ($19,502.98) ($7,372.79)

3:30 380 319.0061 191.31 $15,257.26 513 ($24,535.51) ($9,278.24)

3:45 380 316.4442 130.64 $10,335.07 513 ($16,754.58) ($6,419.51)

4:00 400 314.0429 124.72 $9,791.86 513 ($15,995.34) ($6,203.48)

4:15 400 342.6532 57.23 $4,902.51 513 ($7,339.75) ($2,437.24)

4:30 410 340.2185 38.63 $3,285.66 513 ($4,954.30) ($1,668.64)

4:45 390 336.5086 195.11 $16,414.05 513 ($25,022.86) ($8,608.81)

5:00 370 328.466 1020.52 $83,801.53 513 ($130,881.69) ($47,080.16)

5:15 370 497.031 0 $0.00 513 $0.00 $0.00

5:30 400 484.7868 0 $0.00 513 $0.00 $0.00

5:45 450 469.6484 0 $0.00 513 $0.00 $0.00

6:00 450 450.8654 0 $0.00 513 $0.00 $0.00

6:15 9999 402.5651 0 $0.00 513 $0.00 $0.00

6:30 9999 388.3698 0 $0.00 513 $0.00 $0.00

$155,918.13 ($244,987.00) ($89,068.87)


30

2004 Auction Total Revenues W-N S-N S-H N-H E-N

Annual $18,266,528.01$493,362.1

4$5,066,699.9

2 $6,597,486.72$2,901,444.5

3$3,207,534.7

0

January $839,550.13 $20,811.54 $209,008.81 $213,698.58 $129,084.00 $266,947.20

February $577,990.44 $11,575.37 $168,512.91 $174,072.73 $0.00 $223,829.42

March $1,284,884.09 $65,498.78 $0.00 $352,844.98 $0.00 $866,540.33

April $1,540,363.60 $30,344.68 $108,543.84 $508,367.15 $149,114.49 $743,993.45

May $2,028,690.98 $12,547.77 $295,080.89 $553,266.67 $24,362.14$1,143,433.5

1

June $1,405,099.01 $24,356.51 $301,527.36 $963,827.41 $84,200.76 $31,186.97

July $2,827,311.04 $24,918.17 $671,374.55 $1,432,122.62 $568,917.83 $129,977.87

August $1,693,186.18 $45,083.16 $312,693.16 $814,746.34 $383,068.33 $137,595.19

September $731,937.19 $20,959.56 $0.00 $546,395.03 $164,582.60 $0.00

October $1,064,492.31 $23,388.25 $0.00 $828,435.16 $176,275.99 $36,392.91

November $1,221,575.75 $41,726.70 $0.00 $777,077.68 $284,077.81 $118,693.56

December $1,036,694.42 $39,793.29 $127,649.53 $575,084.70 $253,623.19 $40,543.72

Total $34,518,303.16$854,365.9

2$7,261,090.9

6$14,337,425.7

7$5,118,751.6

8$6,946,668.8

3

2004 ERCOT TCR AuctionsYear to Date Revenues


31

Daily CSC limits vs TCRsAnnual TCRs include PCRs

0

200

400

600

800

1000

1200


S-NAnnual TCRs

Daily OC0 Limit

Total TCRs

Monthly OC0

0

500

1000

1500

2000

2500


S-HAnnual TCRs

Daily OC0 Limit

Total TCRs

Monthly OC0

0

500

1000

1500

2000

2500

3000


N-HAnnual TCRs

Daily OC0 Limit

Total TCRs

Monthly OC0

0

100

200

300

400

500

600

700

800


W-NAnnual TCRs

Daily OC0 Limit

Total TCRs

Monthly OC0

Documents

December 2, 2004 Congestion Causes and Effects Presented to WMS January 14, 2005 Beth Garza