ERCOT 2009 CSC Proposal 3hERCOT 2009 CSC Proposal 3h

Mark Garrett – Direct EnergyMark Garrett – Direct EnergyClayton Greer – J AronClayton Greer – J Aron

2

ERCOT Contour Plot – Proposal 3h

3

ERCOT Transmission Map – 3 CSC Proposals

Bates

J.L. Bates

Frontera

4

What historical data will be representative of 2009 conditions?

Static wire replacement outages on Graham - Abilene - Morgan Creek double circuit 345kV path resulted in major W-N transmission congestion during period from 2/4 through 3/30 and is not expected to be repeated during 2009.

– February-March W-N zonal congestion cost totals $34,153,644.

PRR 764 was implemented on June 9, 2008, removing non-CREs from the zonal solution.

– 2008 W-N Non-CRE zonal congestion cost totals $7,953,061 (excludes Feb-March)

Long Creek Substation was looped into Sweetwater Cogen - Graham 345 kV line on June 3, 2008.

– This change 1) equalized flows on Graham – Long Creek circuits #1 and #2, 2) increased the flow on the Mulberry Creek – Long Creek, and 3) exacerbated the congestion on the Mulberry Creek – Long Creek.

No major outages in 2009 are scheduled per TPIT or Outage Scheduler. If Clear Crossing work results in an outage on Tonkawa – Graham, then Mulberry Creek – Long Creek carries a heavier burden.

5

What historical data will be representative of 2009 conditions? (continued)

Exclude Feb-Mar 2008 due to static wire outage.

Ignore Non-CRE congestion.

W-N topology was significantly reconfigured on June 3 and will remain constant through 2009.

THEREFORE, June 3 to date is the most representative historical data.

6

June transmission flows were a result of high wind outputERCOT Total Wind Output

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

4/1/

2008

0:0

0

4/4/

2008

14:

00

4/8/

2008

4:0

0

4/11

/200

8

4/15

/200

8 8:

00

4/18

/200

8

4/22

/200

8

4/26

/200

8 2:

00

4/29

/200

8

5/3/

2008

6:0

0

5/6/

2008

20:

00

5/10

/200

8

5/14

/200

8 0:

00

5/17

/200

8

5/21

/200

8 4:

00

5/24

/200

8

5/28

/200

8 8:

00

5/31

/200

8

6/4/

2008

12:

00

6/8/

2008

2:0

0

6/11

/200

8

6/15

/200

8 6:

00

6/18

/200

8

6/22

/200

8

6/26

/200

8 0:

00

6/29

/200

8

7/3/

2008

4:0

0

7/6/

2008

18:

00

7/10

/200

8 8:

00

7/13

/200

8

7/17

/200

8

7/21

/200

8 2:

00

7/24

/200

8

7/28

/200

8 6:

00

7/31

/200

8

8/4/

2008

10:

00

8/8/

2008

0:0

0

8/11

/200

8

June 4-8 Avg=3,649MW

4/1-8/11 Avg=1,883MW

7

Electrical Flows on relevant lines – May 30 through June 5

Bastrop

Graham Line Flow (all flows stated West -> North)

-100

0

100

200

300

400

500

600

700

5/30/2008 5/31/2008 6/1/2008 6/2/2008 6/3/2008 6/4/2008 6/5/2008

Sweetwater to Graham Long Creek to Graham

Flows converge on June 3 after 2-day outage to tie-in Long Creek

8

Flows on Mulberry Creek – Long Creek have increased

Configuration before June 3

Configuration after June 3

Note increase after June 3

Note flows equalize after June 3

9

Historical congestion cost – June 3 to present

West To North Congestion ChargesJun 3 - Aug 10, 2008

Occurrences - Days

SCKT Fisher Road – Oklaunion & Bowman

345 kV

DCKT Graham – Benbrook & Parker 345

kV

DCKT Graham – Long Creek 1&2 345 kV

Dynamic Stability

Abilene Mulberry Creek – Long Creek 345 kV - 3h 3h - 13 days

Graham –Murray 138 kV line - 3g 3g - 1 day

Willow Creek - Parker 345 kV line - 3b 3b - 6 days

Dynamic Stability 3 days

Total Occurrences 23 days

Congestion Cost - $

SCKT Fisher Road – Oklaunion & Bowman

345 kV

DCKT Graham – Benbrook & Parker 345

kV

DCKT Graham – Long Creek 1&2 345 kV

Dynamic Stability

Abilene Mulberry Creek – Long Creek 345 kV - 3h $12,278,903

Graham –Murray 138 kV line - 3g $104,044

Willow Creek - Parker 345 kV line - 3b $2,290,343

Dynamic Stability $1,577,897

Total Charges $16,251,187

OV

ER

LO

AD

OV

ER

LO

AD

OUTAGE

OUTAGE

10

Historical congestion days – June 3 to present

Thermal Constraint (3b)

Thermal Constraint (3g)

Thermal

Constraint (3h)

Dynamic Stability Only

June 1 day 0 days 9 days 5 days (local)

July 3 days 1 day 4 days 3 days (zonal)

August 2 days 0 days 0 days 0 days

Total 6 days 1 day 13 days 8 days

Percent Total 21% 4% 46% 29%

Percent Thermal 30% 5% 65% N/A

11

Projected congestion data – calendar year 2009

[RESULTS FROM PRODUCTION COST STUDY FORTHCOMING.]

12

Proposal 3h is the most efficient outcomeImportance of Making the Right Decision

Zonal construct assumes average impact from generation in a zone Physics doesn’t match (hence the change to nodal) Generation sitting on constraint receiving wrong price signal has multiplicative effect due to shift

factor difference

Constraint

Best Counterflow

North Zone

Zonal Average CounterflowWest Zone

13

Result - Proposal 3h is the most efficient outcome

Generator with highest beneficial shift factor receives negative price signal That generator reduces generation (to zero) That beneficial generation must be replaced by moving up the stack not only the

amount of the generation, but by the shift factor difference For example, 400 MWs is located at Long Creek and has twice the positive impact on

the constraint as the North Zone (shift factor difference is an estimate only) With Long Creek in West Zone, the North Zone must not only replace the 400MWs

Long Creek moves down, but must also provide an additional 400MWs due to the solution being less efficient

With Long Creek in the North Zone, this 800 MWs would not have to have been moved at all

Result if decision is wrong is increased spreads and volatility The converse is also true, which is why we need to get this right

Balancing Deployment with Right Decision

Balancing Deployment with Wrong Decision

= ==

14

More wind coming in 2009 in the west

Howard

Borden

Taylor

Shackleford

Cottle

Coke

Pecos

Andrews

Dawson Scurry

SterlingEctor

Nolan

Martin

Dickens

STERLING

• Sterling Energy Center – 200MW – PL

• Sterling Energy Center 2 – 300MW – PL

COTTLE

• Wild Horse Wind Farm 1 – 60MW – IA

• Wild Horse Wind Farm 2 – 39MW – IA DICKENS

• McAdoo Energy Center 2 – 500MW – PL

MARTIN

• Lenorah – 350MW – PL

NOLAN

• Turkey Track Energy Center – 170MW – IA

• Buffalo Gap 4 – 131MW – PL

• Buffalo Gap 5 – 335MW – PL

TAYLOR

• South Trent –101MW – IA

ECTOR

• Pistol Hill – 300MW – PL

• Notrees – 151MW - IA

DAWSON

• Lamesa Wind Plant – 183MW – IA

ANDREWS

• M Bar Wind – 194MW – PL

PECOS

• Sherbino Mesa Wind Farm 1 – 150MW – IA

SHACKLEFORD

• Mesquite 4 (Cottonwood) – 100MW – IA

• Mesquite 5 (Cedar Elm) – 136MW – IA

• Hackberry – 165MW – IA

HOWARD

• Panther Creek – 150MW – IA

• Ocotillo – 59MW – IA

• Gunsight Mountain – 120MW – IA

• Panther Creek 2 – 220MW – IA

• Elbow Creek – 117MW – IA

COKE

• Capricorn Ridge 3 – 249MW – IA

BORDEN

• Bull Creek – 180MW – IA

• Gray Wind – 141MW – PL

• Coyote Run – 225MW – IA

• Wind Tex (Stephens Wind Farm) – 141MW - PL

SCURRY

• Airtricity Inadale – 212MW – IA

• Pyron – 303MW – IA

UPCOMING WIND PROJECTS in Western ERCOT

JUNE 2008 – DEC 2009

3,090 MW : Interconnection Agreement

2,592 MW : Public Letter

Total : 5,682 MW

CSC Scenario #3H

• Abilene Mulberry Creek – Long Creek

• Sweetwater Cogen – Long Creek

15

Conclusion

W-N transmission topology for 2009 was reconfigured on June 3, 2008.

Thermal congestion since June 3 was primarily on Abilene Mulberry Creek – Long Creek : 13 out of 20 days.

CSC selection process should give generators correct price signals to reduce total congestion cost by locating generators in the correct congestion zone.

Abilene Mulberry Creek – Long Creek CSC in Scenario 3h will reduce congestion costs more than Scenarios 3b or 3g.

Scenario 3h is the optimal scenario for the W_N and N_W CSC interface