1. Southeastern Region Transmission Planning 2009 SERTP Economic Studies

2. 2009 SERTP Economic Planning Studies

3. 2009 SERTP Five Economic Planning Studies  North Georgia to FRCC 650 MW650 MW  SCE&G to Georgia 1000 MW1000 MW  Gulfport, MS to Georgia 1000 MW1000 MW  Washington County, GA to Georgia 5000 MW5000 MW  Savannah, GA to Southern Balancing Authority 400 MW Summer Peak400 MW Summer Peak 1000 MW Off Peak1000 MW Off Peak

4. 2009 SERTP Power Flow Cases Utilized  Study year: 2014  Load Flow Cases: 2009 Series Version 2A2009 Series Version 2A Summer Peak with 2250 MW Interchange to FRCC, 3600 MW to FRCC, and ShoulderSummer Peak with 2250 MW Interchange to FRCC, 3600 MW to FRCC, and Shoulder

5. 2009 SERTP Five Economic Planning Studies  Final Report Components: Thermal AnalysisThermal Analysis DC contingency analysis to attain monitored/contingency pairs with Siemens PSS MUSTDC contingency analysis to attain monitored/contingency pairs with Siemens PSS MUST AC verified with Siemens PTI PSS/EAC verified with Siemens PTI PSS/E Interface Transfer Capability ImpactsInterface Transfer Capability Impacts Stability ImpactsStability Impacts Potential SolutionsPotential Solutions Transmission Projects and Cost EstimatesTransmission Projects and Cost Estimates

6. 2009 SERTP The following information does not represent a commitment to proceed with the recommended enhancements nor implies that the recommended enhancements could be implemented by the study date of 2014.The following information does not represent a commitment to proceed with the recommended enhancements nor implies that the recommended enhancements could be implemented by the study date of 2014. These potential solutions only address constraints identified within the Southern Balancing Area that are associated with the proposed transfers. Other Balancing Areas were not monitored which could result in additional limitations and required system enhancements.

7. North Georgia toFRCC 650 MW

8. North Georgia to FRCC: 650 MW Transfer Type: Generation to LoadTransfer Type: Generation to Load Source: 500 kV, Murray County, GASource: 500 kV, Murray County, GA Sink: 650 MW of FRCC load scaled upSink: 650 MW of FRCC load scaled up 488 MW Florida Power & Light488 MW Florida Power & Light 162 MW Progress Energy Florida162 MW Progress Energy Florida Source Sink

9. North Georgia to FRCC: 650 MW Transfer Type: Generation to LoadTransfer Type: Generation to Load Source: 500 kV, Murray County, GASource: 500 kV, Murray County, GA Sink: 650 MW of FRCC load scaled upSink: 650 MW of FRCC load scaled up 488 MW Florida Power & Light488 MW Florida Power & Light 162 MW Progress Energy Florida162 MW Progress Energy Florida 650 MW

10. North Georgia to FRCC: 650 MW Transmission System Impacts  Thermal Constraints Identified: One (1) 500kV LineOne (1) 500kV Line One (1) 230 kV LineOne (1) 230 kV Line Six (6) 115 kV LinesSix (6) 115 kV Lines  Interface Constraints Identified: One (1) 500 / 230 kV TransformerOne (1) 500 / 230 kV Transformer One (1) 230 kV LineOne (1) 230 kV Line  Stability Constraints Identified: None IdentifiedNone Identified

11. Thermal Constraints

12. Interface Constraints

14. North Georgia to FRCC: 650 MW 1 Limiting element is within FRCC Item Potential Project Cost P1 North Americus – North Tifton 115 kV TL $1,350,000 P2 Douglas – Kettle Creek 115 kV TL $900,000 P3 Thalmann – Duval 500 kV TL N/A 1 P4 Lloyd Shoals – South Griffin 115 kV TL $500,000 P5 Barneyville – Pine Grove 115 kV TL $250,000 P6 Mitchell – Moultrie 115 kV TL $3,000,000 P7 Jasper – Pine Grove 115 kV TL $11,000,000 I1 North Tifton 500 / 230 kV Substation $36,000,000 I2 Woodstock 230 kV Substation $100,000 Total Cost: $53,100,000 Transmission Project Estimates

15. Potential Enhancements P1 P6 P2 P5 P7

16. Potential Enhancements I1

17. Potential Enhancements I2

18. SCE&GtoGeorgia 1000 MW

19. SCE&G to Georgia: 1000 MW Transfer Type: Load to GenerationTransfer Type: Load to Generation Source: SCE&G LoadSource: SCE&G Load Sink: Georgia GenerationSink: Georgia Generation Source Sink

20. SCE&G to Georgia: 1000 MW Transmission System Impacts  Thermal Constraints Identified: One (1) 230 / 115 kV TransformerOne (1) 230 / 115 kV Transformer One (1) 115 kV LineOne (1) 115 kV Line  Interface Constraints Identified: One (1) 500 / 230 kV TransformerOne (1) 500 / 230 kV Transformer Two (2) 230 kV LinesTwo (2) 230 kV Lines One (1) 230 / 115 kV TransformerOne (1) 230 / 115 kV Transformer Four (4) 115 kV LinesFour (4) 115 kV Lines  Stability Constraints Identified: None IdentifiedNone Identified

21. Thermal Constraints CENTER

22. Interface Constraints

23. SCE&G to Georgia: 1000 MW Item Potential Project Cost P1 Avalon Junction – Bio 115 kV TL $3,800,000 P2 Gainesville #2 115 kV Substation $200,000 I1 Athena – Hartwell 230 kV TL $44,000,000 I2 Center Primary 230 kV Substation $300,000 Athena 230 kV Substation Total Cost: $48,300,000 Transmission Project Estimates

24. SCE&G to Georgia: 1000 MW Item Potential Project Cost P1 Avalon Junction – Bio 115 kV TL $3,800,000 P2 Gainesville #2 115 kV Substation $200,000 I1 Athena – Hartwell 230 kV TL 1 $44,000,000 I2 Center Primary 230 kV Substation $300,000 Athena 230 kV Substation Total Cost: $44,500,000 Transmission Project Estimates 1 Project I1 alleviates the need for Project P1

25. Potential Enhancements CENTER P1 P2

26. Potential Enhancements I1 I2 P1 P2

27. Gulfport, MS toGeorgia 1000 MW

28. Source Sink Gulfport, MS to Georgia: 1000 MW Transfer Type: Generation to GenerationTransfer Type: Generation to Generation Source: 500 kV, Harrison County, MSSource: 500 kV, Harrison County, MS Sink: Georgia GenerationSink: Georgia Generation

29. Gulfport, MS to Georgia: 1000 MW Transfer Type: Generation to GenerationTransfer Type: Generation to Generation Source: 500 kV, Harrison County, MSSource: 500 kV, Harrison County, MS Sink: Georgia GenerationSink: Georgia Generation 1000 MW

30. Stability Enhancements P1

31. Gulfport, MS to Georgia: 1000 MW Transmission System Impacts  Thermal Constraints Identified 1 : Six (6) 230 kV LinesSix (6) 230 kV Lines Nine (9) 115 kV LinesNine (9) 115 kV Lines  Interface Constraints Identified 2 : Two (2) 230 kV LinesTwo (2) 230 kV Lines 1 Constraints remaining after implementing stability enhancement 2 Constraints remaining after implementing all thermal enhancements

32. Gulfport, MS to Georgia: 1000 MW Transmission System Impacts Continued  Stability Constraints Identified: With the additional transfer of 1000 MW from Gulfport, MS to the Georgia ITS, a fault on the Daniel – McKnight 500 kV transmission line could result in all of the units within the local area to pull out of synchronism with the rest of the Eastern Interconnect.With the additional transfer of 1000 MW from Gulfport, MS to the Georgia ITS, a fault on the Daniel – McKnight 500 kV transmission line could result in all of the units within the local area to pull out of synchronism with the rest of the Eastern Interconnect.

33. Constraints After Stability Enhancements

35. Interface Constraints

37. Gulfport, MS to Georgia: 1000 MW Item Potential Project Cost P1 Daniel – Snowdoun 500 kV TL $340,000,000 P2 Daniel – Bennett 230 kV TL $23,000,000 P3 Barry - Crist 230 kV TL $2,200,000 P4 South Montgomery – Union Spring 115 kV TL $3,500,000 P5 Pike County – Snowdoun 230 kV TL $18,300,000 P6 Farley – South Bainbridge 230 kV TL $2,500,000 P7 Anniston – Bynum 230 kV TL $10,000,000 P8 Bull Creek – Victory Drive 115 kV TL $2,500,000 P9 Crooked Creek – Martin Dam 115 kV TL $8,500,000 P10 Madison Park – Thurlow Dam 115 kV TL $750,000 ……Continued…… Transmission Project Estimates

38. Gulfport, MS to Georgia: 1000 MW Item Potential Project Cost …...Continued……. P11 South Bainbridge 230 kV Substation $20,000,000 P12 Bainbridge Area 115 kV Network Enhancements $5,000,000 I1 Bennett – North Theodore 230 kV TL $760,000 I2 Goat Rock – Fortson 230 kV TL $20,000,000 Transmission Project Estimates Total Cost: $457,010,000

39. Potential Enhancements P1 P2 P3 P6 P9 P5 P8 P4 P10 P11 P12 I1

40. Potential Enhancements I2

41. Washington County toGeorgia 5000 MW

42. Source Sink Washington Co. to Georgia: 5000 MW Transfer Type: Generation to GenerationTransfer Type: Generation to Generation Source: Washington County, GASource: Washington County, GA Sink: Georgia GenerationSink: Georgia Generation

43. Washington Co. to Georgia: 5000 MW Transfer Type: Generation to GenerationTransfer Type: Generation to Generation Source: Washington County, GASource: Washington County, GA Sink: Georgia GenerationSink: Georgia Generation 5000 MW

44. Washington Co. to Georgia: 5000 MW Transmission System Impacts  Thermal Constraints Identified: Ten (10) 500 kV LinesTen (10) 500 kV Lines Four (4) 500 / 230 kV TransformersFour (4) 500 / 230 kV Transformers Thirty (30) 230 kV LinesThirty (30) 230 kV Lines Six (6) 230kV / 115 kV TransformersSix (6) 230kV / 115 kV Transformers Twenty-three (23) 115 kV LinesTwenty-three (23) 115 kV Lines  Interface Constraints Identified: Three (3) 230 kV LinesThree (3) 230 kV Lines  Stability Constraints Identified: None IdentifiedNone Identified

45. Thermal Constraints

46. Potential Enhancements (P1) P1

47. Thermal Constraints After P1

48. Potential Enhancements (P1 through P3) P3 P2 P1

49. Thermal Constraints After P3

50. Interface Constraints

52. Washington Co. to Georgia: 5000 MW Item Potential Project Cost P1 1 Yr. Advancement of Bethabara 230 / 115 kV Project from 2015 $3,200,000 1 Yr. Advancement of East Walton 500 / 230 kV Project from 2015 $13,300,000 P2 East Walton – South Hall 500 kV TL $54,500,000 P3 Rockville – ECO2 500 kV TL $81,700,000 P4 3 Yr. Advancement of the Middlefork – Thomson 500 kV TL $47,300,000 P5 Wilson 230 kV Substation $300,000 P6 Vogtle 500 / 230 kV Substation $35,300,000 P7 Waynesboro 230 / 115 kV Substation $50,000 P8 Jesup – Ludowici Primary 115 kV TL $1,750,000 ……Continued…… Transmission Project Estimates

53. Washington Co. to Georgia: 5000 MW Item Potential Project Cost ……Continued…… I1 Wadley Primary – Waynesboro Primary 230 kV TL $500,000 I2 Dum Jon – Goshen 230 kV TL $500,000 I3 Goat Rock – Fortson 230 kV TL $20,000,000 Total Cost: $258,400,000 Transmission Project Estimates

54. Potential Enhancements (P1 through P8) P4 P5 P6 P7 P3 P2 P1

55. Potential Enhancements I1 I2

56. Potential Enhancements I3

57. Savannah, GA to Southern Balancing Authority 400 MW – Summer Peak 1000 MW – Off Peak

58. Source Sink Savannah, GA to Southern Balancing Authority Transfer Type: Generation to GenerationTransfer Type: Generation to Generation Source: Savannah, GASource: Savannah, GA Sink: Southern Balancing AuthoritySink: Southern Balancing Authority

59. Savannah, GA to Southern Balancing Authority Transfer Type: Generation to GenerationTransfer Type: Generation to Generation Source: Savannah, GASource: Savannah, GA Sink: Southern Balancing AuthoritySink: Southern Balancing Authority 400 MW Summer 1000 MW Off Peak

60. Savannah, GA to SBA 400 MW Summer Peak Transmission System Impacts  Constraints Identified: Two (2) 230kV LinesTwo (2) 230kV Lines One (1) 115kV LineOne (1) 115kV Line  Interface Constraints Identified: None IdentifiedNone Identified  Stability Constraints Identified: None IdentifiedNone Identified

61. Thermal Constraints

62. Savannah, GA to SBA 400 MW Summer Peak Item Potential Project Cost P1 1 Yr. Advancement of the Bethabara 230/115kV Project from 2015 $3,200,000 1 Yr. Advancement of the East Walton 500/230 kV Project from 2015 $13,300,000 P2 Athena – Union Point 115kV TL $11,300,000 Total Cost: $27,800,000 Transmission Project Estimates

63. Potential Enhancements P2 P1

64. Savannah, GA to SBA 1000 MW Off Peak Transmission System Impacts  Thermal Constraints Identified: One (1) 115kV LineOne (1) 115kV Line  Interface Constraints Identified: None IdentifiedNone Identified  Stability Constraints Identified: None IdentifiedNone Identified

65. Thermal Constraints

66. Savannah, GA to SBA 1000 MW Off Peak Item Potential Project Cost P1 McIntosh – Yemassee 115kV TL $675,000 Total Cost: $675,000 Transmission Project Estimates

67. Potential Enhancements P1

68. 2009 SERTP Project Cost Summary  North Georgia to FRCC $53,100,000$53,100,000  SCE&G to Georgia $44,500,000$44,500,000  Gulfport, MS to Georgia $457,010,000$457,010,000  Washington County to Georgia $258,400,000$258,400,000  Savannah, GA to Southern Balancing Authority $28,475,000$28,475,000 $27,800,000 for Summer Peak$27,800,000 for Summer Peak $675,000 for Off Peak$675,000 for Off Peak

69. Questions?