Houston Region Import
Capacity Project
August 27, 2013
Regional Planning Group Meeting
Background
 Tie line capability limited to approximately 6500 MW currently
 Generation
‾ Previously or currently mothballed units: 1367 MW
‾ Additional units approaching 50 years old: 1174 MW
‾ Recent generation additions have been relatively small
‾ Houston is a non-attainment zone
‾ Proposed Pondera (1300 -1380MW) has not provided Notice
to Proceed since signing SGIA in 2010
 Recent ERCOT publications (2012 Constraints and Needs report
and 2012 Long Term Study) show need for additional import path
into Houston
 CNP has serious concerns about reliability/resource adequacy for
the Houston load pocket because of limited import capability
1
Older Units
Possible future retirements - a total of 1939 MW in-service units will be older
than 50 years by 2018. These resources were modeled as online in the
Study Case.
2
Houston Load Pocket Projected Reserves
Note: Resources include both generation and import capacity into Houston
3
Study Approach
Phase I: Study Case Analysis
 Modify SSWG 2015-2018 base cases created in February 2013
- Remove Pondera (1300 MW)
- Add Deer Park Energy Center expansion (215 MW)
- Add Calpine Energy Center expansion (200 MW)
- CNP load matches 2012 ALDR (other than new transmission
customers)
• Non-coincident peak
• Hot summer load level (102 degree F)
• 2013 ALDR CNP load about 600 MW higher in 2018 than in 2012
ALDR
• CNP studying over 1000 MW of industrial load not included in 2013
ALDR which could be on-line as early as 2016
4
Study Approach
Phase I: Study Case Analysis
 Use ERCOT Criteria: Planning Guide 4.1.1.2 (1)(b)
- Take largest unit inside Houston “zone” out of service: Cedar Bayou Unit
2 (745 MW)
- Perform Single and Common Mode contingencies (Common tower
outage)
· Overload of Singleton – Zenith circuits beginning in 2018
(100.8% in 2018)
Emergency Loading %
** From bus ** ** To bus ** CKT
Rating Yr 2015 Yr 2016 Yr 2017 Yr 2018 Contingency Description
44645 SNGLTN_345 345 44900 ZENITH__345A 345 98 1450.0
95.2
95.9
100.8
TOMBALL 345 SINGLETON & KING ROANS PRAIRIE
44645 SNGLTN_345 345 44900 ZENITH__345A 345 99 1450.0
95.3
95.9
100.8
TOMBALL 345 SINGLETON & KING ROANS PRAIRIE
5
Houston Region
Phase I: Study Case Analysis
Cedar Bayou 2 out-of-service
Year
Peak Load (MW)
Peak Transmission Losses (MW)
Peak Demand (MW)
Installed Capacity w/o CB2 (MW)
Previously and Currently Mothballed (MW)
Average Import Capacity From 138 and 345 kV
Ties (MW)
Planned Resources with Signed IA, Air Permit,
and Securitized Deposit per Table 2-1 (MW)
Total Resources (MW)
Surplus/Deficit (MW)
Additional Reserve/Deficit Margin
2015
2016
2017
2018
19111
19331
19525
19726
291
319
330
346
19402
19650
19855
20072
11706
11706
11706
11706
1367
1367
1367
1367
6500
6500
6500
6500
415
415
415
415
19988
19988
19988
19988
586
338
133
(84)
3.07%
1.75%
0.68%
-0.43%
6
Phase I: Reliability Analysis – CB2 out
Sensitivity Analysis
 Without 1367 MW mothballed generation – loading of 114% for year 2015
** From bus ** ** To bus ** CKT
Emergency Loading %
Type Rating Yr 2015 Yr 2016 Yr 2017 Yr 2018
44645 SNGLTN_345 345 44900 ZENITH__345A 345 98
LN
1450.0
114.3
121.4
124.1
134.3
44645 SNGLTN_345 345 44900 ZENITH__345A 345 99
LN
1450.0
114.3
121.5
124.2
134.4
44650 SMTHRS__345A 345 47000 BELAIR__345A 345
98
LN
44645 SNGLTN_345 to 46500 TOMBAL__345B 345 74
1137
1924.0
96.2
95.2
97.8
99.4
102.0
103.1
108.5
Contingency Description
TOMBALL 345 - SINGLETON &
KING - ROANS PRAIRIE
TOMBALL 345 - SINGLETON &
KING - ROANS PRAIRIE
BELLAIRE 345 - JEANETTA 345
CKT.64 & BELLAIRE 345 - WA
PARISH 345 CKT.50
SINGLETON - ZENITH 345
CKT.98 & SINGLETON - ZENITH
345 CKT.99
 New 500 MW generator inside CNP – loading of 92% for year 2018
Emergency Loading %
** From bus ** ** To bus ** CKT
Rating Yr 2015 Yr 2016 Yr 2017 Yr 2018
44645 SNGLTN_345 345 44900 ZENITH__345A 345 98
1450.0
87.0
87.5
92.2
44645 SNGLTN_345 345 44900 ZENITH__345A 345 99
1450.0
87.0
87.5
92.2
Contingency Description
TOMBALL 345 - SINGLETON & KING - ROANS
PRAIRIE
TOMBALL 345 - SINGLETON & KING - ROANS
PRAIRIE
7
Study Approach
 Phase II: Interconnection Options and Initial Screening
– Evaluate transfer capability of the 2018 Study Case and 25 Options
– Use ERCOT 2012 average transmission costs to estimate each option
- Include estimated costs of reinforcements
– Rank Options based on Transfer Improvement Value (MW transfer
increase) / (Cost)
– Select best Options for additional analysis
 Phase III: Interconnection Options Detailed Analysis
– Evaluate voltage stability impacts and estimate reactive compensation for
each Option
– AC Contingency and Short-circuit analysis
– Prepare detailed cost estimates using typical CenterPoint Energy costs
 Identify preferred interconnection options that maximize increased
transfer capability versus total project cost
8
Twenty-five Options Studied
Options 1 - 16
Jordan
9
Twenty-five Options Studied
Options 17 – 25
10
Comparison of Electrical Alternatives
11
Five Options Selected for Further
Study
21
12
Phase III: Additional Studies
Detailed Cost Analysis
13
Three Preferred Interconnection
Options
Preferred Interconnection Options
Transfer
Increase
(MW)
New 345 kV
Cost ($ MM) MW/$ MM
Structure-miles **
Option 15 : Twin Oak-Zenith (including system
improvements)
2701
117
462
5.85
Option 24 : Ragan Creek-Zenith* (including
system improvements)
1960
69
297
6.60
Option 25 : Limestone-Ragan Creek-Zenith*
(including system improvements)
2532
130
532
4.76
*Ragan Creek is a future 345 kV Switching Station to be constructed as part of the interconnection option.
**New 345 kV structure-miles include a 20 percent increase from their point-to-point straight-line distances to account for
uncertainty in routing.
14
System Configuration – Option 15
Option 15: Twin Oak – Zenith 345 kV
G
Limestone
G
Jewett
Twin Oak
TNPONE
Jack Creek
G
G
Gibbons Creek
Singleton
ROANS PR
2018
Bobvle
Tomball
G
Zenith
T.H.W
North
Belt
15
System Configuration - Option 24
Option 24: Zenith – Ragan Creek 345 kV
G
Limestone
G
Jewett
Nucor
Twin Oak
Jack Creek
Ragan Creek
G
G
Gibbons Creek
Singleton
ROANS PR
2018
Bobvle
Tomball
G
Zenith
T.H.W
North
Belt
16
System Configuration - Option 25
Option 25: Limestone - Ragan Creek – Zenith 345 kV
G
Limestone
G
Jewett
Nucor
Twin Oak
Jack Creek
Ragan Creek
G
G
Gibbons Creek
Singleton
ROANS PR
2018
Bobvle
Tomball
G
Zenith
T.H. W
North
Belt
17
Conclusions
 Unless additional net generation or new import transmission
paths into Houston region are constructed CNP will not comply
with ERCOT’s Planning Criteria by year 2018.
 25 interconnection options studied. Three options are
recommended based on technical and economical analysis.
18
Conclusions
– Option 15: New Twin Oak - Zenith 345 kV double circuit:
2700 MW transfer capability improvement. $462 million project cost.
5.85 MW/$MM transfer/cost value. New line connects Oncor’s and
CNP’s substations. Includes approximately $7.5 million in LCRA 138
kV line upgrades.
– Option 24: New Ragan Creek – Zenith 345 kV double circuit:
1960 MW transfer capability improvement. $297 million project cost.
6.60 MW/$MM transfer/cost value. New line connects CNP’s Zenith
substation to a new 345 kV Ragan Creek substation. Includes $5
million upgrade of TMPA Twin Oak - Jack Creek -Ragan Creek
double circuit. Includes approximately $2 million in LCRA 138 kV
line upgrades.
– Option 25: New Limestone – Ragan Creek - Zenith 345 kV
double circuit: 2530 MW transfer capability improvement. $532
million project cost. 4.76 MW/$MM transfer/cost value. New line
connects Limestone to new 345 kV Ragan Creek substation to
Zenith substation. Includes approximately $5.5 million of LCRA 138
kV line upgrades.
19
Questions?