October 16, 2009

RPG Meeting

ERCOT RPG Project Review Update

Jeff Billo

RPG Meeting October 16, 2009 2

RPG Project Review Update

• Recommendation Letter sent for:

– CenterPoint Garrott-Midtown-Polk Upgrade Project (Tier 3)

– CenterPoint 2012 Northwest Houston Reliability Project (Tier 2)

• ERCOT Independent Review nearly complete for:

– AEPSC Corpus Christi Improvements (Tier 1)

• Comment period in process for:

– Brazos Electric Kruegerville-Frisco (Tier 3)

• ERCOT Independent Review in process for:

– Sharyland ERCOT Southeast Loop (Tier 1) [part of 2009 5YTP]

– CenterPoint North-Houston Constraint Mitigation Project (Tier 1) [part of 2009 5YTP]

– Oncor Lamesa Area Upgrades (Tier 1) [part of 2009 5YTP]

– Luminant Energy Comanche Peak Congestion Mitigation (Tier 2)

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RPG Project Review Update

• Other projects under review

– Oncor Comanche Peak 3 and 4 Additions Project (Tier 1)• ERCOT Independent Review will be completed after 2009 5YTP

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Northwest Houston Reliability Project

CenterPoint Energy Northwest Houston Reliability Project

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Northwest Houston Reliability Project

• CenterPoint Energy proposed the Northwest Houston Reliability Project to resolve reliability problems in the area due to expected load growth

• Original proposed in-service date was 2012

• New load forecasts show lower load predictions through 2014

Model/Case

2012 Updated

December 2007

2012 Updated

June 2009

2013 Updated

June 2009

2014 Updated

June 2009

Area Load (MW)

2443.35 2105.85 2162.96 2220.07

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Northwest Houston Reliability Project

• ERCOT Independent Review (using June 2009 SSWG base cases) showed no reliability problems in the area in 2012 and 2013

• 2014 analysis revealed the need for the following upgrades to relieve post-contingency overloads (Option 1):– Install a new 345/138 kV 800 MVA autotransformer at T.H. Wharton in

parallel with the existing 800 MVA autotransformer # 1

– Convert Klein substation to a breaker substation and build a new 138 kV circuit from T.H. Wharton to Klein

– Reconductor circuit 76 Cy-Fair to Kluge

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Northwest Houston Reliability Project Option 1

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Northwest Houston Reliability Project

• As an alternative ERCOT tested a modified version of CenterPoint Energy’s preferred solution (Option 2):– Expand 345 kV Zenith to 345/138 kV substation and install a new 345/138

kV 800/1000 MVA autotransformer

– Build a new 138 kV double circuit from the new 138 kV Zenith substation to Gertie Row and connect to existing 138 kV double circuits to Gertie

– Reconfigure the existing 138 kV circuit 76 from Kluge to Addicks and circuit 21 from Kluge to Camron to create three new 138 kV circuits: circuit 1 from Zenith to Addicks, circuit 2 from Zenith to Kluge and circuit 21 from Kluge to Camron

– Reconductor circuit 2 Cy-Fair to Kluge

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Northwest Houston Reliability Project Option 2

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Northwest Houston Reliability Project

• Both options solved reliability problems in 2014• Cost

– Option 1 = $25.3 million– Option 2 = $25.5 million

• No congestion in area: projects did not create or relieve any congestion• Option 2 provides new 345 kV to 138 kV injection point• Option 2 alleviates the loss of 400 MW of load due to single tower

(double circuit) contingency• CenterPoint Energy’s analysis revealed that with future load growth

Option 2 will require fewer upgrades in the long run• ERCOT recommended Option 2 as the preferred solution

– Recommended 2014 but could be 2013 if load growth increases sooner

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2009 Houston Import Study

Houston Import Study

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2009 Houston Import Study

• Why are we studying this?

– ERCOT Independent Review of Sharyland’s ERCOT Southeast Loop RPG Project (Tier 1)

– ERCOT 2009 Five-Year Transmission Plan Economic Analysis

– Ongoing congestion in real-time

– ERCOT Independent Review of Centerpoint’s North to Houston Constraint Mitigation RPG Project (Tier 1)

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2009 Houston Import Study Assumptions

• Study Assumptions

– Base case = 2009 5YTP 2014 Economic Start Case• Includes all 2009 5YTP reliability projects identified for 2014

• Includes all CREZ transmission facilities

• Does not include additional CREZ generation

– Analysis will focus on economic benefit of additional import capacity into Houston area per ERCOT RPG Charter and Procedures Section 3.3

• UPLAN

• Assumed load can be served reliably without additional import capability, but additional import project may allow reliability criteria to be met at a lower overall cost

– Interface limits used as proxy for voltage stability limits

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2009 Houston Import Study

• Approach

Base CaseBase Case BC + CREZ Generation

BC + CREZ Generation

BC + STP 3 & 4

BC + STP 3 & 4

BC + New Gas Gen North of Houston

BC + New Gas Gen North of Houston

BC + New Gas Gen In

Houston

BC + New Gas Gen In

Houston

BC + Load Variation

BC + Load Variation

BC + Comanche Peak 3 & 4

BC + Comanche Peak 3 & 4

Bulk of analysis will focus on the base case. Options may be eliminated at this

stage.

Alternate scenarios will be used to quantify relative merit of options

that pass first stage. Final recommendation will be selected.

Sensitivity scenarios will be run for recommended option and results added to report.

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2009 Houston Import Study Options

1 Lufkin-Canal 345-kV double circuit

2 Salem-Zenith 345-kV double circuit

3 Fayetteville-Zenith 345-kV double circuit

3A Fayetteville-Zenith 345-kV double circuit w/ 30% series comp

4 Gibbons Creek-Zenith 345-kV double circuit

6 Fayetteville-Obrien 345-kV double circuit

6A Fayetteville-Obrien 345-kV double circuit w/ 30% series comp

9 Gibbons Creek-Salem-Zenith 345-kV double circuit

12 Gibbons Creek-Salem/ Fayetteville-Zenith 345-kV double circuit

19 Add series comp to existing Hillje-WAP and Hillje-Holman 345-kV

22 Fayetteville-Zenith 345-kV double circuit w/ 50% series comp

24 Option 19 + Option 22

J1 Sandow-Zenith 345-kV double circuit

J1A Sandow-Zenith 345-kV double circuit w/ 30% series comp

J2 Marion-Holman-Obrien 345-kV double circuit

J3 Hillje-Obrien 345-kV double circuit

DC Brown-Zenith 3000 MW HVDC line

E1 Twin Oaks-Salem-Zenith 345-kV double circuit

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2009 Houston Import Study Options

To BrownOption 1Option 2Option 3/ 3A/ 22Option 4Option 6/ 6AOption 9Option 12Option 19Option J1/ J1AOption J2Option J3Option DCOption E1

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2009 Houston Import Study

• Initial findings– Initial results indicated little savings until other 5YTP upgrades

implemented

– Upgrading/ adding import paths into Houston from the south did not produce significant savings

• Options 19, 24, and J3 are no longer being considered

– Adding import paths into Houston from the north and/ or west revealed significant production cost savings but not enough to justify the cost of the project using the societal benefit test

• However, some did produce enough energy revenue (consumer benefit) savings to justify the cost of project

– Per ERCOT RPG Charter and Procedures Section 3.3

– Relaxing N-H and S-H voltage constraints generally increased the production cost and energy revenue savings

• Comments?

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Savings with voltage constraints (preliminary)

OptionsTotal Cost ($

million)

Savings Needed ($

million)PC Savings ($

million)

Energy Revenue

Savings ($ million)

         

1 429 71.50 20.56 44.06

2 258 43.00 1.28 47.03

3 222 37.00 -4.38 55.54

3A 241 40.17 7.00  64.08

4 226 37.67 12.34 -27.96

6 244 40.67 10.81 22.52

6A 263 43.83 17.44 15.77

9 380 63.33 5.25 41.48

12 370 61.67 12.80 65.17

22 241 40.17 2.04 66.23

J1 359 59.80 11.79 23.40

J1A 378 63.00 18.73 26.35

J2 390 65.00 15.39 24.56

E1 462 77.00 19.23 31.10

DC  n/a n/a n/a n/a

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Savings without voltage constraints (preliminary)

OptionsTotal Cost ($

million)

Savings Needed ($

million)PC Savings ($

million)

Energy Revenue

Savings ($ million)

         

1 429 71.50 22.25 71.56

2 258 43.00 7.07 56.73

3 222 37.00 12.13 45.35

3A 241 40.17 19.59 79.86

4 226 37.67 12.36 -14.02

6 244 40.67 16.79 47.41

6A 263 43.83 11.08 52.8

9 380 63.33 12.41 86.23

12 370 61.67 16.91 89.45

22 241 40.17 17.75 78.7

J1 359 59.80 16.99 47.28

J1A 378 63.00 20.33 75.94

J2 390 65.00 17.78 77.41

E1 462 77.00 17.5 90.19

DC  n/a n/a n/a n/a

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2009 Houston Import Study

• Issues for comment

– Is it appropriate to apply voltage stability constraints to 2014 case?

– How should Category D contingency of Zenith substation outage be considered?

– Which options can be dropped from further analysis based on the Base Case production cost savings or energy revenue savings?

• Next Steps

– Finalize base case analysis

– Test options that pass first step in alternate scenarios

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Questions?