Jan 13, 2012 RPG Meeting El Campo – Vanderbilt 69 kV Project – Status report Ehsan Ur Rehman Planning Engineer ERCOT

2 Jan. 13, 2012RPG Meeting Project Background Jackson Electric Cooperative (JEC) Load addition Areas surrounded by Jackson, Victoria and Wharton Counties are part of Eagle Ford shale formation and are newly discovered oil exploration areas Oil reserves are estimated to be 3 billion barrels and is said to be the sixth largest oil field discovered in the USA Oil and gas exploration leads towards significant amount of load addition Approx. 118 MW of new electric load will be added in Jackson County, TX by the end of 2013 Existing 69kV (STEC) system is composed of 4/0 ACSR conductor (45MVA) and cannot support the new load addition

3 RPG Meeting Jan 13, 2012 Map of the Area of concern

4 Jan. 13, 2012RPG Meeting Base Case Model & Assumptions Study Cases The latest 2014 & 2016 Reliability Cases from the YTP Load Changes Load was updated/increased in the area of concern based on STEC’s submittal 2016 Case:- STEC load: 1503 MW 2014 Case:- STEC load: 1395 MW Generation Changes Monticello 1 & 2 (in-service) Sam Bertron 1 & 2 (in-service) Greensbayou 5 (in-service) Panda Temple 1 (not available in 2014) All other mothballed units (turned off)

5 RPG Meeting Jan 13, 2012 Overloads on existing system due to updated loading in 2014

6 Jan 13, 2012RPG Meeting Project Options Option 1 (345 kV) Build a new 345 kV station near Cordelle and loop the STP – Elm Creek 345 kV line into it Add a 345/138 kV auto-transformer Build a new 138 kV line (approx. 1.5 miles) to the new load serving 138/24.9 kV distribution system Add 9.6 Mvar capacitor banks at Cordele and Ganado Switch Total Cost :- $24.5 million Facts The load will be radially connected to the 345 kV station The 18.7 MW of load at Cordelle 69 kV still requires Vanderbilt – Eltoro and Ricebird – Round Mott 69 kV line to be upgraded No New load can be served through the existing weak 69 kV transmission system without these upgrades

7 RPG Meeting Jan 13, 2012 Option 1 (345 kV) topology with entire load moved to the new distribution station

8 RPG Meeting Jan 13, 2012 Loading after moving the Cordelle load (18.7 MW) served radial from 345 kV (2016 case)

9 Jan 13, 2012RPG Meeting Project Options (Cont.) Option 2 (69/138 kV rebuild) Rebuild the existing 69 kV line (22 miles) from El Campo and Cordelle as a double circuit 69 KV & 138 kV with 122 MVA and 240 MVA (emergency rating); respectively Rebuild the existing 69 kV line (13 miles) from Cordelle and El Toro switch as a double circuit 69 KV & 138 kV with 122 MVA and 240 MVA (emergency rating); respectively Rebuild the existing 69 kV line (13.6 miles) from El Toro and Vanderbilt switch as a double circuit 69 KV & 138 kV with 122 MVA and 240 MVA (emergency rating); respectively Install 9.6 Mvars of capacitor banks at Louisville 69 kV, Ganado 69 kV, Cordele 69 kV and ETP sub 138kV Construct a new 138 kV double circuit line (on a new R.O.W) from the ETP substation to a single new 84 MW load Total Cost :- $ million

10 Jan 13, 2012RPG Meeting Option 2 Upgrades

11 RPG Meeting Jan 13, 2012 Option 2 (n-1) results for 2014

12 RPG Meeting Jan 13, 2012 Option 2 (n-1) results for 2016

13 Jan 13, 2012RPG Meeting G-1 analysis for Option 2 Option 2 (rebuilding of existing 69 kV and adding 138kV lines) was analyzed under G-1 conditions The biggest combined cycle train at Colorado Bend (252 MW) was turned off. Nursery – Rayburn 69 kV line was shown overloaded in both 2014 and 2016

14 Jan 13, 2012RPG Meeting Facts about Option 2 upgrades Load will not be radially connected with Option 2 More load can be connected to the 69 kV system with Option 2 in future Nursery – Rayburn 69 kV line has to be upgraded with Option 2 upgrades

15 Jan 13, 2012RPG Meeting Summary Rebuilding the existing 69 kV transmission system (Option 2 upgrades) seems to be a better option as additional load may be connected to the existing 69 kV substations in future. However, after performing the G-1 analysis, it is mandatory to include Nursery – Rayburn 69 kV upgrade as a part of Option 2 Upgrades to serve future loads additions. Thus the final Option 2 Upgrades are listed on the following slide

16 Jan 13, 2012RPG Meeting Summary (Cont.) Updated Option 2 Upgrades (69/138 kV rebuild) Rebuild the existing 69 kV line (22 miles) from El Campo and Cordelle as a double circuit 69 KV & 138 kV with 122 MVA and 240 MVA (emergency rating); respectively Rebuild the existing 69 kV line (13 miles) from Cordelle and El Toro switch as a double circuit 69 KV & 138 kV with 122 MVA and 240 MVA (emergency rating); respectively Rebuild the existing 69 kV line (13.6 miles) from El Toro and Vanderbilt switch as a double circuit 69 KV & 138 kV with 122 MVA and 240 MVA (emergency rating); respectively Install 9.6 Mvars of capacitor banks at Louisville 69 kV, Ganado 69 kV, Cordele 69 kV and ETP sub 138kV Construct a new 138 kV double circuit line (on a new R.O.W) from the ETP substation to a single new 84 MW load Upgrade Nursery – Rayburn 69 kV line such the the Circuit Rate B is 122 MVA Total Updated Cost :- $ million

17 September 17, 2010RPG Meeting March 12, 2010 Questions?