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Entergy Arkansas, Inc.
Proposed Transmission Projects
Entergy Transmission Planning Summit New Orleans, LA July 31, 2007
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2007 - 2008 EAI Transmission Projects
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1.) Hilltop: New Ring Bus at Intersection of EAI and SPA lines
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2.) Dewitt Capacitor Bank
Carryover from 2006 2007/2008 Projects 2
2009-2010 EAI Transmission Projects 1.) Grandview 161kV Substation
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2.) Dell 161kV Reactor Replacement 3.) Cabot 500/115kV Substation
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2011-2012 EAI Transmission Projects 1.) Gobel - 230/115 kV Substation
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2.) Re-conductor 115kV Transmission Line from Corning to Texas Eastern #8
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Hilltop: 161 kV Ring Bus Between EAI and SPA Lines
2007 Scenario: • The 161 kV transmission system in northwest Arkansas is generally served by generation located at Arkansas Nuclear One (ANO) and Independence SES (ISES).
• There are also units at Table Rock, Ozark Beach, Norfork and Bull Shoals Dam which provide some support during the summer peak, but availability of these resources is limited by the availability of water on their respective sources.
• Three major transmission lines which originate at Harrison East and cause undervoltages and thermal overloads: – Harrison East – Eureka Springs 161 kV – Harrison East – Bull Shoals Dam 161 kV – Harrison East – Quitman 161 kV Proposed Solution: • Build a four-breaker ring bus, Hilltop, where the SPA line from Dardanelle Bull Shoals crosses the APL line from Harrison East - Quitman. Estimated Cost: $8.6 M 5
Hilltop: 161 kV Ring Bus Hilltop: Install New Ring Bus
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Thayer South: Install New 161 kV Intertie w/ AECI
• Project Cancelled – AECI elected to connect to an existing AECI owned 161kV Station 7
Thayer South: Install New 161 kV Intertie w/ AECI (Cancelled)
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2008
Dewitt: 32.4 MVAR Capacitor Bank
Scenario: • Loss of the Helena Industrial - Ritchie SES 115 kV line segment causes low voltages at various substations • Loss of the Stuttgart Ricusky 230/115 kV autotransformer causes low voltages at various substations and overloads on the Woodward – Altheimer and the Altheimer – Wabbaseka 115 kV line segments Proposed Solution: • Install a 32.4 MVAR capacitor bank at Dewitt.
• Correct Distribution power factor at Dewitt, Almyra, Marvell, Gillett, Helena Central, and Ulm substations.
Estimated Cost: $880 K 9
Dewitt: 32.4 MVAR Capacitor Bank Dewitt: 32.4 MVAR Capacitor Bank
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Maumelle East Substation: Install 2 nd T-Line
Scenario: • Significant load growth in the Maumelle area justified removing Maumelle East from radial service.
• The loss of the Maumelle East – Maumelle SS line results in a complete outage to the Maumelle area.
2008 Proposed Solution: • Construct a parallel 115kV line from Maumelle SS to Maumelle East to establish dual line service.
Estimated Cost: $3 M 11
Maumelle East: 2 nd Transmission Line Maumelle East 2 nd Line
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2010
Dell 161kV Reactor Replacement
Scenario: • The 161kV reactor at Dell failed late 2006.
• During off-peak, low load periods, the voltage at Dell EHV reaches 1.05pu on the 500kV and 161kV systems.
Proposed Solution: • The failed 161kV 50MVAR reactor at Dell will be replaced with 2-161kV, 30 MVAR reactors Estimated Cost: $1.5 M 13
Dell 161kV Reactor Replace Dell 161kV Reactor
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2010
Osage Creek-Grandview
Scenario: • By 2010 it is estimated that approximately 227 MW of load will be served between Harrison East and Eureka Springs. • Nearly 110 MW of the load will be located at Osage Creek, at the extreme northwest end of the line. • Loss of the Harrison East – Harrison South transmission line segment causes thermal overloads by as much as 7% on the Eureka – Osage Creek (AECC) line segment and leaves over 30 MW at risk.
• Loss of this line also causes Osage’s voltage drop to 73%.
Proposed Solution: • Construct a new switching station, Grandview, on the transmission line from Table Rock Dam – Eureka Springs. Build a new line between Grandview and Osage Creek.
Estimated Cost: $5.8 M 15
Osage Creek-Grandview Grandview
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2010
Cabot 500/115kV Substation
Scenario: • For the past two summers, several stations in Little Rock observed voltages as low as 91% of nominal with no significant contingencies.
• The loss of one of the 500/115kV transformers at Mabelvale in 2006 resulted in widespread low voltages in the Little Rock area.
• With the loss of one 500/115kV transformer at Mabelvale, a loss of the second transformer (N-2) would cause the voltage to collapse and widespread outages in the Little Rock area.
Proposed Solution: • Construct a 500/115kV substation near Cabot Northeast of Little Rock. This will provide voltage support to Little Rock and reduce some thermal contingencies.
Estimated Cost: $19 M 17
Cabot 500/115kV Substation
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Cabot EHV
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Gobel 230/115 kV Substation
Scenario: • Loss of the Helena Industrial - Ritchie SES 115 kV line segment causes – Low voltages at Helena Central, Barton, Marvell, Elaine, Gillette, Deluce, and Dewitt • Loss of the Stuttgart Rickusky 230/115 kV autotransformer causes – Low voltages at Almyra, Deluce, Gilette, Dewitt, Stuttgart North, Stuttgart Ricusky, Ulm, Wabbaseka, and Stuttgart Industrial – Overloads the Woodward – Altheimer 115 kV line segment – Overloads the Altheimer – Wabbaseka 115 kV line segment Proposed Solution: • Build a 230/115kV Substation at the crossing of the 115kV transmission line from Marvell to Elaine and the 230kV transmission line from Ritchie to Stuttgart Ricusky.
Estimated Cost: $9 M 19
Gobel 230/115 kV Substation Gobel 230/115kV Substation
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2011
Re-conductor Corning - Texas Eastern #8 115 kV line
Scenario: • Previous construction has increased the conductor size on selected spans to 1590 MCM and 666 MCM, but a majority of the line is 336 MCM or smaller (e.g., 4/0 copper), and substation equipment limits the ampacity of the line.
• The voltage drop from TE #8 to Corning exceeds 22% under certain single contingency scenarios. • Low voltage also causes greater current to flow and will cause a 190% overload on the Corning to TE #8 line segment.
Proposed Solution: • Rebuild the line segment from Corning to TE #8 with 666 MCM, to increase the line rating to 176 MVA.
Estimated Cost: $3 M 21
Re-conductor Corning - Texas Eastern #8 115 kV line Upgrade 115kV Line
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Transmission System Target Areas 2013 and Beyond 1.) Jonesboro Area
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Line Upgrade
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2.) Little Rock Area
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Additional Reactive Support
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3.) Hot Springs Area
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Line Upgrade
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New 115kV Switching Station
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4.) El Dorado Area
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2 New 115kV Transmission Lines
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Line Upgrades
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