ERCOT 2009 Five-Year Transmission Plan Update

1. ERCOT 2009 Five-Year Transmission Plan Update Jeff Billo RPG Meeting

2. 2009 Five-Year Transmission Plan: Where we’re at = Complete = In Process = Not Started RPG Meeting

3. 2009 Five-Year Transmission Plan Reliability Analysis • Two significant project changes since last update • Changed Alliance 345/138-kV autotransformer project to Hicks 345/138-kV autotransformer project • Changed addition of second 345/138-kV autotransformer to Mustang 345-kV station and autotransformer project • Miscellaneous reliability project changes since last update based on comments from Transmission Owners RPG Meeting

4. Hicks 345/138-kV autotransformer project • Reliability Issue: One Roanoke 345/138 kV autotransformer overloads for the loss of the other Roanoke 345/138 kV autotransformer in 2013 and 2014 • Not feasible to replace both Roanoke autotransformers or add a third autotransformer • Additional need to add transmission southwest of Roanoke for load growth needs RPG Meeting

5. Hicks 345/138-kV autotransformer project • Two options studied: • Build new 345/138 kV station near Alliance; construct double circuit 138 kV line from new station to new load serving stations to Elizabeth Creek • Cost = $21.5M + cost of new 138 kV double circuit • Construct a 138 kV bus at the new Hicks CREZ station and install a 345/138 kV autotransformer, construct double circuit 138 kV line from Hicks to new load serving stations to Elizabeth Creek • Cost = $11.0 M + cost of new 138 kV double circuit • Length of new 138 kV double circuit roughly the same for both options so cost assumed to be the same • Both options tested in 5YTP 2014 economic case with and without CREZ generation • Hicks option resulted in production cost savings of $2.12M in 2014 economic benchmark case • Hicks option resulted in production cost savings of $3.75M in 2014 economic case with CREZ generation • Savings resulted from reduction in congestion on the Hicks-Alliance 345 kV line for the contingency of Hicks-Roanoke 345 kV line • Option 2 (Hicks) recommended as preferred option RPG Meeting

6. Mustang 345 kV station project • 2014 Reliability Issues: • Collin 345/138 kV autotransformer overloads for the contingency loss of Collin-Carrollton Northwest 345 kV line • Low voltages on Kruegerville-Frisco 138 kV line for the contingency loss of Collin-Frisco 138 kV line • Existing series reactor at Collin (SPS) does not relieve overload in 2014 RPG Meeting

7. Mustang 345 kV station project • Two options studied • Add second 345/138 kV autotransformer at Collin, install shunt capacitors on Kruegerville-Frisco line • Existing stations on Kruegerville-Frisco line not sized for capacitor bank additions • Cost ~ $11-12M • Create a 345 kV bus at Mustang, loop one circuit the Anna-Krum West 345 kV CREZ line into Mustang, install a 345/138 kV autotransformer at Mustang • Cost ~ $18.5M • Other considerations • High load growth area • Mustang option (Option 2) provides support to east side of Denton loop • Mitigates the need to reconductor Pockrus-Denton Steam 138-kV line (<$1M) • Option 2 recommended as preferred option RPG Meeting

8. 2009 Five-Year Transmission Plan Economic Analysis 2014 Economic Projects RPG Meeting

9. 2009 Five-Year Transmission Plan Economic Analysis • 2014 Changes since August RPG Meeting • Various model corrections and updates (see posted spreadsheet: “2009 5YTP Economics 2014 Project Set 09182009.xls”) • Changed Horse Hollow 3 to inject into Kendall (via NextEra private 345 kV line) • To relieve congestion due to contingency loss of one Bluff Creek 345/138 kV autotransformer overloading the other Bluff Creek autotransformer • Not economic to switch more Horse Hollow generation to Kendall due to congestion near Kendall • Ten economic projects: RPG Meeting

10. 2009 Five-Year Transmission Plan 2014 Economic Analysis Select Projects RPG Meeting

11. Alvin area projects • New 345/138 kV station and autotransformer scheduled to be constructed at Meadow (formerly South Alvin) in May 2010 • Congestion expected on 138 kV lines exiting Meadow towards the east for contingency loss of Meadow-PH Robinson 345 kV line • Congestion expected on Oasis-Meadow-PH Robinson 345 kV line for contingency loss of Cedar Bayou-Chambers/ Cedar Bayou-North Belt 345 kV double circuit and n-0 RPG Meeting

12. Alvin area projects • CenterPoint has TPIT project to uprate Oasis-PH Robinson 345 kV line by end of 2009 • 5YTP economic recommendations: • Add second circuit to Oasis-Meadow 345 kV line • Cost = $4.9M • 2014 PC Savings = $2.8M • Ratio = 1.75 < 6 • Upgrade Alvin Tie (Meadow)-Alvin and Alvin Tie (Meadow)-Hastings-Friendswood-Seminole-Magnolia • Cost = $21.2M • 2011 PC Savings = $5.2M • Ratio = 4.08 < 6 *Alvin Tie (Meadow)-Hastings 138 kV line upgrade is a reliability project in 2014 RPG Meeting

13. Lower Panhandle Project • Congestion on lines exiting the Whirlwind and McAdoo wind generation plants • Daily Operations • 5YTP models Whirlwind – 60 MW McAdoo – 150 MW RPG Meeting

14. Lower Panhandle Project • 5YTP Solution – Construct project to separate wind power from load serving system and instead inject to CREZ system • Waiting for cost estimates to determine if economic Whirlwind ~ Matador Cottonwood (Pan A-D) Spur McAdoo ~ RPG Meeting

15. 2009 5YTP Next Steps • Finish Analysis by October 30 • Report First Draft by November 13 RPG Meeting

16. Questions? RPG Meeting