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2014 LTSA UpdateOctober 21, 2014

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Outline

LTSA update

Case summary

Reliability analysis results

Next steps

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LTSA Update

Four scenarios were shortlisted for transmission analysis based on

stakeholder feedback

Current Trends (CT)

High Economic Growth (HEG)

Stringent Environmental (SE)

Global Recession (GR)

Reliability cases were prepared per the LTSA scope

Final 2013 RTP case for the year 2018 was used as a start case

90th percentile load forecast by weather zone was used for the cases

Additional generation was added based on the outcome of generation

expansion analysis

Generation siting methodology was used to keep siting consistent

across scenarios

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Case Summary: 2029 Reliability Case (summer peak)

Scenario Load Generation* Solar Wind

CT 88782 88774 7241 646

HEG 95984 98991 11189 508

GR 84022 79141 3839 517

SE 88842 86542 11540 1011

*Total generation available for reliability analysis under summer peak condition per the LTSA scope

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Impact of solar adds

The LTSA scenario assumptions lead to

significant solar additions in the next decade

Amount of utility solar increases from 150 MW to

about 10,000 MW

Solar output is known to be co-incident with the

demand

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Impact of solar adds on the load shape

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Reliability Analysis Summary (Preliminary Results)

Study Region Constrained Element

Scenarios Where Violated

Years Where Violated

CT SE GR 2024 2029

Coast

Surfsi – Quintana – Freeport 138-kV Line X X X X X

Jordan – Cities – Winfree – Brine – Langston – Mont Belvieu 138-kV Line X X X X

Greenbelt – Tejas – Comanche 138-kV Line X X X X

Dow 345/138-kV Autotransformers A1 and A2 X X X

South Texas – Dow 345-kV Lines X X

Peters – Foster – Flewellen 138-kV Line X X

EastMt Enterprise – Trinidad 345-kV Line X X

Richland – Big Brown 345-kV Line X X

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Reliability Analysis Summary (Preliminary Results)

Study Region Constrained Element

Scenarios Where Violated

Years Where Violated

CT SE GR 2024 2029

North Central

Hicks Switch – Alliance / Roanoke 345-kV double circuit line X X -  -  X

Benbrook 345/138-kV autotransformers X X X  - X

Collin Switch 345/138-kV autotransformer #1 X X -  X X

Northwest Carrollton 345/138-kV autotransformer   X - -  X

Eagle Mountain SES 345/138-kV autotransformers X X -  - X

Hicks Switch 345/138-kV autotransformer X X X X X

Roanoke Switch 345/138-kV autotransformers X X X   X

Royse Switch 345/138-kV autotransformers X -  -  X - 

West Uvalde – W. Batesville 138 kV line X X XBrackettville – Hamilton 138-kV line X X

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Reliability Analysis Summary (Preliminary Results)

Study Region Constrained Element

Scenarios Where Violated

Years Where Violated

CT HE SE GR 2024 2029

South

La Palma 345/138-kV autotransformer and surrounding 138-kV lines

X X X X

Loma Alta 345/138-kV autotransformer and surrounding 138-kV lines

X X X X

South Central

Clear Springs - Marion - Skyline 345-kV line X X

Bracken 345/138-kV autotransformer X X

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Next steps

Complete N-1, G-1 + N-1 and X-1 + N-1 reliability

analysis

Compile list of reliability projects for different scenarios

Complete economic analysis

Summarize results in the 2014 LTSA