Lower Rio Grande Valley 345 kV line€“The Cross-Valley 345 kV line enabled the ... Rio Bravo San...

Lower Rio Grande Valley

345 kV line

ERCOT Regional Planning Group

May 13, 2011

Prepared by AEPSC on behalf of ETT

5/13/2011 Prepared by AEPSC 2

South Texas Transmission

Infrastructure• Drivers for development

– Shrinking windows for maintenance/clearances

– Availability of generation during high demand

– Development of infrastructure along the border

• Staging the plan for South Texas– Completion of San Miguel to Laredo Lobo in 2010

– Linking Laredo to the Valley

– Maximizing delivery capability of existing system

– Closing the loop within load pockets

• South Texas Transmission Infrastructure Benefits – Enabling access to economic resources and renewable energy

– Laredo: Two is better than One

– Valley: Three is better than Two


Drivers for development

• Shrinking windows for maintenance and/or clearances– N-1-1 windows are practically limited to March and November

– Operational load forecast for February 4th did not anticipate the need for all generation in the Valley

– 345 kV line clearances to replace corroded components nearly displaced STEC 138 kV upgrades within the Valley

• Availability of generation during high demand– Only one plant is located on the east side of the Valley

– Recent information creates the need to plan for a plant outage

– Valley import level exceeded security limit an average of 6 days per year for the last four years resulting in high scarcity pricing

– Forward looking CRR pricing anticipates further congestion

• Development of infrastructure along the border – Within ten years infrastructure additions will be needed in Laredo

– Over 1 GW of wind has already connected in South Texas

– Over 1 GW of new wind is negotiating interconnection agreements


Staging the plan for South Texas

• Completion of San Miguel to Laredo Lobo– Relieved RMR in Laredo in 2010

– Reversed power flow into Valley from west improving voltage stability for Valley

• Linking Laredo to the Valley– The Cross-Valley 345 kV line enabled the two existing 345 kV

lines to share import into the Valley

– Similarly, the Laredo to Valley 345 kV line enables both load pockets to share import among three lines

– As a result, Voltage Stability limits are elevated well beyond thermal constraints


Proposed Laredo to Valley 345 kV Project


Power/Voltage Profile for Ajo to Rio Hondo 345 kV

line contingency and one unit unavailable

2210 2360 2520 2680 2840 2990 3150 3310 3470Valley Load

300 MW Increase 300 MW Increase

Proposed Plan

2015 P

eak L

oad

(25% Compensation)


Linking Laredo to the Valley

Interface between

South Texas and

ERCOT

Interface between

East and West

sides of the Valley

Relief of localized

constraints with

new infrastructure



• Maximizing delivery capability of existing system– The existing Valley 345 kV lines are undersized

relative to the new third line

– High temperature composite core conductor can virtually double the rating of the existing lines

– Series Capacitors can be reconfigured to double the rating, at half compensation level

– Due to improved voltage stability and new SSCI issues, lower compensation is viable

– Lower compensation improves the thermal import limit by balancing power flow between existing lines

– Potentially, Lon Hill to Nelson Sharpe to Ajo to Rio Hondo 345 kV line may be rebuilt due to corrosion



• Closing the loop within load pockets

– Third line from Laredo to the Valley enables

localized loops to serve growth within load

pockets

• Lobo to Rio Bravo relieves voltage collapse on

south side of Laredo

• Del Sol to Frontera relieves contingency overloads

in McAllen

– Future loop within the Valley addresses

support of the eastern end


Loss of the Gateway to University / North Laredo double

circuit 138 kV line results in voltage collapse

Double Circuit 138 kV line contingency

Area of Voltage Collapse

Feed from Valley at Roma

Proposed 138 (345) kV line


LRGV West Side Constraint

Limiting Element: HEC

to SEd 138 kV line

G-1: 2682 MW (2016)

P-1: 2573 MW (2015)

Contingency:

NEd to Pharr /

WEd 138 kV line

Del Sol

Del Sol


Second Cross-Valley line links

East and West sides of the LRGV

2/15/11 DRAFT REV 1 3

DEL SOL

FRONTERA

NORTH

EDINBURG

LOBO

RIO BRAVO

Double Circuit

Double Circuit

Capable

SAN MIGUEL

RIO HONDO

Double Circuit

Capable

345 kV

138 kV

69 kV

New Station

Existing Station

New Line



Infrastructure Benefits • Enabling access to economic resources and renewable

energy– Enables the transfer of power in and out of South Texas and

lowers marginal costs to consumers

– Improves access to low cost wind resources that contribute across peak load periods

– Creates infrastructure that allows ERCOT and CFE to share capacity during periods of scarcity


Improves access to low cost wind resources

that contribute across peak load periods

Rio Bravo

San Ygnacio

Randado

Zapata

Lopeno

Falcon SS

Roma SS

Wormser

Lobo

Gateway

University

Santo Nino

Sierra Vista

North Laredo

Wind Regions

Rio Bravo

San Ygnacio

Randado

Zapata

Lopeno

Falcon SS

Roma SS

Wormser

Lobo

Gateway

University

Santo Nino

Sierra Vista

North Laredo

Wind Regions

CFE

CFE

Enables Capacity

exchange between

ERCOT and CFE

during scarcity



Infrastructure Benefits • Laredo: Two is better than One

– Load growth in Laredo is limited to 600 MW (2021) assuming availability of one of two combustion turbines

– Load growth in Laredo is limited to 500 MW (2013) assuming availability of neither of the two combustion turbines

– Extreme Summer peak demand can achieve 600 MW in 2018


Existing Transmission System

Load Serving Capability in Laredo

100%

97%96%

92%

88%

97%

94%

100%99%

96%

80%

85%

90%

95%

100%

105%

Lon Hill to

Straton

Straton to

KRPG

Pearsall to

Palo Duro

Dilley to

Cotulla

Cotulla to

Encinal

138 kV Limiting Elements

% E

merg

en

cy R

ati

ng

Lobo to San Miguel + 1/2 MVEC (578 MW)

Lobo to San Miguel + Laredo #4 (600 MW)


2011 Laredo Area Summer Peak Load

Forecast at Varying Probability Intervals

(G-1

)


2011 Laredo Area Winter Peak Load


(P-1

)



Infrastructure Benefits

• Valley: Three is better than Two

– Opening clearance windows enables upgrades to

existing Valley 345 kV lines

• N-1-1: clearance on the Ajo to Rio Hondo and contingency of

the Lon Hill to North Edinburg

• Current 138 kV constraint of 300 MW doubles to 600 MW

with the third 345 kV line

– Combined effect of new line with upgrades to existing

lines doubles import capability

• Constraint: One Valley 345 kV line overloads the remaining

Valley 345 kV line

• Voltage stability limits are well in excess of thermal limitations


Opening clearance windows enables

upgrades to existing 345 kV lines to Valley

0%

2%

3%

5%

6%

8%

9%

11%

12%

14%

15%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Pro

bab

ility

of b

ein

g th

e A

nn

ual

Pea

k

Per

cen

tage

of A

nn

ual

Pea

k

Valley - Historical Peak Days and ProbabilitiesBased on Valley Load Data excluding PUB since 1996

Historical Maximum of Daily Peak as a Percentage of Annual Peak

Probability of being the Annual Peak

Increasing N-1-1 import

capability by 300 MW (10%)

doubles the window

available for clearances



Load Serving Capability in the Valley

25232623

2688 2733

25882678

2488

23432271

2331 2370 2411

2251 2286 2316 2336

0

500

1000

1500

2000

2500

3000

50% 33% 17% 0%

Compensation Levels

MW

Le

ve

l

North Ed to Lon Hill Out G-1

Rio Hondo to Ajo Out G-1

North Ed to Lon Hill Out P-1

Rio Hondo to Ajo Out P-1

Kenedy Wind Farm generation at 600MW

VC



Load Serving Capability in the Valley

2601

26512691

2726

2316

23762416

2436

2100

2200

2300

2400

2500

2600

2700

2800

50% 33% 17% 0%

Compensation Levels

MW

Level

North Ed to Lon Hill Out G-1

North Ed to Lon Hill Out P-1

Kenedy Wind Farm generation at 100MW


(Source: http://www.ercot.com/news/press_releases/2010/nr-11-17-10#_Toc277772169).

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

50/50 Peak 2,362 2,426 2,501 2,573 2,656 2,723 2,791 2,847 2,900 2,944

70/30 Peak 2,391 2,455 2,531 2,604 2,688 2,756 2,824 2,881 2,934 2,979

90/10 Peak 2,431 2,497 2,575 2,648 2,734 2,803 2,872 2,930 2,984 3,030

99/1 Peak 2,488 2,555 2,634 2,710 2,797 2,868 2,939 2,998 3,054 3,100

1,000

1,250

1,500

1,750

2,000

2,250

2,500

2,750

3,000

3,250

3,500

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021

Su

mm

er

Peak D

em

an

d in

MW

Actual

Weather Normalized (50/50 Peak)

Mar 2011 Forecast (50/50 Peak)

70/30 Peak

90/10 Peak

99/1 Peak

*Valley includes PUB. PUB data obtained from a presentation for the ERCOT Regional Planning Group "Cross Valley RPG Report_05-01-11_Final.pdf"

90/10 Peak probability means

there is less than a 10% chance

the peak will be above this

value.

2011 Texas Valley* Area Summer Peak Load


(G-1

)


(Source: http://www.ercot.com/news/press_releases/2010/nr-11-17-10#_Toc277772169).

2012 2013 2014 2015 2016 2017 2018 2019 2020

50/50 Peak 2,350 2,426 2,497 2,569 2,626 2,684 2,740 2,793 2,833

70/30 Peak 2,450 2,529 2,603 2,679 2,738 2,799 2,857 2,912 2,954

90/10 Peak 2,595 2,679 2,757 2,837 2,900 2,964 3,026 3,085 3,129

99/1 Peak 2,795 2,885 2,969 3,056 3,123 3,193 3,259 3,322 3,370

1,000

1,250

1,500

1,750

2,000

2,250

2,500

2,750

3,000

3,250

3,500

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021

Win

ter

Peak D

em

an

d in

MW

Actual

Weather Normalized (50/50 Peak)

Mar 2011 Forecast (50/50 Peak)

70/30 Peak

90/10 Peak

99/1 Peak

*Valley includes PUB. PUB data obtained from a presentation for the ERCOT Regional Planning Group "Cross Valley RPG Report_05-01-11_Final.pdf"

90/10 Peak probability means

there is less than a 10% chance the

peak will be above this value.

2011 Texas Valley* Area Winter Peak Load


(G-1

)


Need for Critical Status

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3

CCN Approval

(12 Months)

Environ. Assessment & Routing Study

Create

Study

Areas

Aerial Surveys

(18 Months)

PR

OJE

CT

AU

TH

OR

IZA

TIO

N

Create Routes

Open

Houses

Functional Scoping,

Project Development,

Contracts, Schedule

Routing StudyPlanning / Kick offF

ILE

CC

N

CCN Approval

Permits

ROW Negotiation & Purchase

(10 Months)

(6 Months)

Entry

Line Construction ( 20 months)

ROW Clearing &

Procurement

Engineering &

MA

RC

H 1

, 2016

Pro

ject

Targ

et

Co

mp

leti

on

Date

ROW Acquisition Construction

Condemnations

Road Construction (11 months)

Bound. Surveys & Plat Creation

Lobo - Del Sol - North Edinburg 345kV Transmission Line

2011 2012 2013 2014 2015 2016

Expedited Schedule (May 10, 2011)

• Project team assembled and studies kicked off by end of May 2011.

• Major contractors identified and contracts expedited to begin work.

• Use of internet available aerial data and accept risk of low resolution and non-

current photography for routing studies.

• Expedited testimony for CCN application.

• Possible additional costs to expedite schedule.

• Require immediate ERCOT RPG endorsement and designation as “Critical

Classification” of project..

• PUCT to provides approval within 6 months after filing CCN.

• Right of entry obtained and survey begins before CCN is approved.

• Begin clearing and road construction in advance of all ROW secured.

• Multiple construction fronts with accelerated construction schedule with possible

increase in costs.

• Excellent construction conditions including good weather to yield no construction

interruptions.


Upgrading Existing 345 kV system

from 2000a rating to 4000a

2/15/11 DRAFT REV 1 1FRONTERA

NORTH

EDINBURG

LOBO

Double Circuit

Capable

SAN MIGUEL

Double Circuit

Capable

345 kV

138 kV

69 kV

Existing Station

Reconductor LH-NE

345 kV line w/LH

upgrades: $55M

Reconfigure NE 345 kV

SC w/NE upgrades: $20M

Reconfigure RH 345 kV

SC w/RH upgrades: $20M

Reconductor AJ-RH

345 kV line: $30M

138 kV PST @

Loyola: $5M

Reconductor LH-NS

345 kV line w/LH

upgrades: $15M

Reconductor NS-AJ

345 kV line: $20M

Additional SC at

Rio Bravo: $25M


2523 2593 2643

3133

3373

36513870

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Existing

System

Lobo to Valley

($410)

AJ-RH RC

($50M)

LH-NE RC

($75M)

NS-AJ RC

($20M)

LH-NS RC

($15M)

Cross-Valley

MW

Valley Load served by Stage with

300 MW of generation unavailable


Valley Load served by Stage with

600 MW of generation unavailable

2251 2312 2343

28533063

3451 3500

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Existing

System

Lobo to Valley

($410)

AJ-RH RC

($50M)

LH-NE RC

($75M)

NS-AJ RC

($20M)

LH-NS RC

($15M)

Cross-Valley

MW


0

1000

2000

3000

4000

5000

6000

Lobo to Valley

($410)

AJ-RH RC

($50M)

LH-NE RC

($75M)

NS-AJ RC

($20M)

LH-NS RC

($15M)

$/k

W

Combined effect of new line with upgrades

to existing lines doubles import capability

2021 (

G-1

)

2021 (

P-1

)

Incremental Import Capability relative to Cumulative Cost

MW 70 120 610 850 1128

$M 410 460 535 555 570

Year Capital Cost

2020 $/kW

ADV CC 1,070$

ADV CT 898$

Conv CC 1,039$

Conv CT 807$

Coal 3,380$

Nuclear 6,465$

Solar PV 3,249$

Wind 2,696$

Lower Rio Grande Valley 345 kV line€“The Cross-Valley 345 kV line enabled the ... Rio Bravo San...

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