Entergy Mississippi, Inc. Proposed Transmission Reliability Projects

1. Entergy Mississippi, Inc.Proposed Transmission Reliability Projects Transmission Planning Summit

2. 2007 - 2011 EMI Transmission Reliability Projects Horn Lake – TH Allen 161kV Line Upgrade 2009 Rolling Fork Capacitor Bank 2010 Grenada/Winona/Greenwood Area Improvement 2011 Ray Braswell –Byram 115kV Line 2010 Ridgeland - Madison Reliability Improvement 2010 Natchez SVC and Capacitor Bank 2008 McComb Capacitor Bank 2007 Liberty – Gloster 115 kV 2009 Liberty – Gillsburg 115 kV 2008

3. 2007 McComb:Install 21 MVAr Capacitor Bank Scenario: • The McComb and Tylertown areas are served by three 115 kV lines out of Brookhaven, Bogalusa and Amite. The load in the area in 2008 will be 233 MW. • The single contingency loss of either the Brookhaven – Mallalieu or Mallalieu – Norfield 115 kV lines will cause low voltages at various substations. Recommended Solution: • Install a 21 MVAr capacitor bank at McComb and correct the load power factor to 98% in this area where needed. • Estimated Cost: $750 k

4. McComb 21 MVAr Capacitor Bank

5. 2008 Natchez SES:Install SVC and Capacitor Bank Scenario: • The Natchez area is served by five 115 kV lines out of Franklin, Baxter Wilson, Liberty, Swartz, and Standard. The load in the area in 2008 will be 480 MW. • The single contingency loss of any one of the five lines feeding into the area will cause low voltages at various substations. Recommended Solution: • Install a 60 MVAr capacitor bank at Natchez SES and a +/- 65MVAr Static VAR Compentator. • Estimated Cost: $10 MM

6. Natchez SVC and Capacitor Bank

7. 2008 Liberty - Gillsburg 115 kV: Upgrade Capacity of Line Scenario: • The Liberty - Gillsburg 115kV line, located in southern Mississippi, is approximately 15 miles long and is limited to a rating of 69 MVA. • The loss of the Franklin – Bogalusa EHV line will cause the line to overload. Recommended Solution: • Re-conductor the Liberty – Gillsburg line and increase the rating of the line to 103 MVA. • Estimated Cost: $7 MM

8. Liberty - Gillsburg 115 kV: Upgrade capacity of line

9. 2009 Liberty - Gloster 115 kV: Upgrade Capacity of Line Scenario: • The Liberty - Gloster 115kV line, located in southern Mississippi, is 20 miles long and is limited to a rating of 108 MVA. • The loss of the Franklin – Meadville 115 kV line or the S. Vicksburg – Port Gibson 115 kV line will cause the line to overload. Recommended Solution: • Re-conductor the Liberty – Gloster line and increase the rating of the line to 161 MVA. • Estimated Cost: $4.4 MM

10. Liberty - Gloster 115 kV: Upgrade capacity of line

11. 2009 Horn Lake:Energize 230/161kV Autotransformer & Upgrade Horn Lake – Allen (TVA) 161kV Line Scenario: • The Southaven and Senatobia areas, served by one 230 kV line and two 115 kV lines, will total approximately 398 MW in 2009. • The single contingency loss of the Freeport – Horn Lake 230kV line will cause low voltages at 8 substations. Recommended Solution: • Reconductor the Horn Lake – TH Allen (TVA) 161kV line to a rating of at least 619 MVA and energize the idle 230/161kV autotransformer at Horn Lake. • Estimated Cost: $3.5 MM

12. HornLake 230/161kV Auto & Allen Line Upgrade

13. 2010 Ridgeland-Madison Reliability Improvement Scenario: • The Lakeover- NE Jackson - Rex Brown 115 kV line is 25 miles long and will serve 6 substations totaling 220 MW in 2008. • The loss of the Rex Brown - Hico, Hico - N. Jackson or N. Jackson - Canton Rd 115 kV lines in 2008 causes overloads on the Lakeover - Livingston Rd 115 kV line. Recommended Solution: • Build a 115kV substation in the existing Northpark 230kV substation and cut in the Lakeover-NE Jackson line at Northpark (between Ridgeland and Country Club). Double-Circuit the existing Lakeover–Livingston–Ridgeland 115 kV line, upgrading the existing line to at least 231 MVA, and connect the new circuit to the new 115kV bus at the Northpark substation. This new circuit will be used for the feed to the new Sunnybrook substation. • Estimated Cost: $13 MM

14. Sunnybrook Northpark 115 Ridgeland-Madison Reliability Improvement

15. 2010 Ray Braswell – Byram 115 kV LineConstruction Scenario: • The SW Jackson to Byram to Brookhaven line is 53 miles long and serves 223 MW of load. • The loss of the SW Jackson to Elton or Elton to Byram 115 kV lines will cause overloads on three line sections from Brookhaven to Hazlehurst 115 kV and undervoltages on various buses in 2008. • In addition, the loss of Brookhaven - Wesson or Wesson - James Rd. will cause overloads on two line sections from SW Jackson to Byram. Recommended Solution: • Build an new 115 kV line from Ray Braswell to Byram 115 kV substation with a rating of at least 261 MVA. • Estimated Cost: $23 MM

16. Ray Braswell – Byram115 kV Line Construction

17. 2010 Rolling Fork: Install Capacitor Bank Scenario: • Under N-1 contengencies on the N.Vicksburg to rolling Fork to Greenville lines (183 & 131), the substations along the line experience voltages violations. When either end of the line is open, the buses along the line have low voltages. • The north end (Greenville) of the line being open causes the more extreme results. Recommended Solution: • Install a 21.4 MVAR capacitor bank at the Rolling Fork Substation. • Estimated Cost: $750,000

18. Rolling Fork: Install Capacitor Bank

19. 2011 Tillatoba - South Grenada:Build New 230 kV Line and Install 230/115 Auto at S. Grenada Scenario: • The Greenwood, Winona, and Grenada area is supplied by five 115kV lines and will serve 342 MW in 2009. • The loss of one of these five 115 kV lines or the loss of the Tillatoba 230/115kV auto will cause various bus undervoltages and overloads on 2 115kV lines. Recommended Solution: • Build a 230kV line from Tillatoba to S. Grenada with 1,272 ACSR (or equivalent conductor) and install a 230/115kV autotransformer at S. Grenada. Install additional capacitor banks at Greenwood (32 MVAR) and Winona (21 MVAR). Estimated Cost: $45 MM

20. Tillatoba - S. Grenada: Build New 230 kV Line & South Grenada Auto

21. EMI Transmission System Target Areas 2012 and Beyond • Southhaven Area • Build 2 New 230 kV lines • Hollandale Area • Add Breakers • Close Normally Open Line • Franklin Area • New 230kV Substation • Build 2 New 230kV Lines