1. ERCOT Transmission Planning Overview
Cathey Carter, Tim McGinnis, Ping Yan, Phung Nguyen
ERCOT Transmission Planning

2. Objectives
Identify the new generation coming into ERCOT grid in the next 18 months
Identify newly implemented Generic Transmission Constraints (GTC) in ERCOT system
Identify remaining reliability issues that potentially require Constraint Management Plans (CMP) for 2016
Identify major 345-kV projects expected to be in-service from April 2016 to September 2017
Recognize future system issues identified and studies being done for the Valley and Houston areas

3. Transmission Planning Responsibilities
Generation Interconnection or Change Request (GINR)
Regional Transmission Plan (RTP)
Regional Planning Group (RPG) Reviews
Other Studies such as Long-Term System Assessment (LTSA), Reliability Must Run (RMR) Studies, Dynamic Studies, NERC Compliance Studies, etc

4. Generation Interconnection Requests
As of November 12, 2015, the total capacity under study in ERCOT with the Commercial Operation Date (COD) by the end of June 2017 is MW
The break down of the capacity by generator types:
Gas: 9691 MW
Solar: 6411 MW
Wind: MW
Storage: 20 MW

5. Planning Guide Section 6.9
Executed Standard Generation Interconnection Agreement (SGIA) with Transmission Service Provider (TSP)
Provided sufficient financial commitment and notice to proceed
Air permit / water rights (conventional units only)

6. Project Status
* Based on GINR information as of November 12, 2015

7. Future Generators (MW) with SGIA
* Based on GINR information as of November 12, 2015

8. Generators Completed Planning Requirements1
Briscoe Wind (150 MW) 2
Green Pastures W (300 MW) 3
Shannon Wind (200 MW) 4
Barilla Solar 1B (7MW) 5
Downie Ranch Solar (95 MW) 6
Javelina Wind (250 MW) 7
Sendero Wind (78 MW) 8
Cameron County Wind (165 MW) 9
PHR Peakers (390 MW) 10
Baytown Chiller (270 MW)
* Based on GINR information as of November 12, 2015

9. ERCOT Solar Penetration Study
Since the majority of the solar projects undergoing interconnection studies are located in the West/Far West weather zones where the transmission system is relatively weak, ERCOT is in the process of performing a solar penetration study
The objective of the study is to assess impacts of the solar projects on ERCOT’s current transmission system and get a high level understanding of the needed transmission upgrades to accommodate the solar projects should they come online as planned

10. ERCOT Solar Penetration Study
The solar penetration study will study the solar projects in three stages:
Stage 1: 1352 MW of Solar Projects will be studied
Stage 2: 5166 MW of Solar Projects will be studied
Stage 3: 8979 MW of Solar Projects will be studied
The deliverable of the study is the identification of transmission projects to address issues found for each stage of solar projects
At this time ERCOT does not plan to recommend any specific projects from the study findings. Rather, the study will be used to inform future planning studies

11. Generic Transmission Constraints
Generic Transmission Constraints (GTCs) are used in reliability and market analyses pursuant to Section Use of Generic Transmission Constraints and Generic Transmission Limits of the ERCOT Nodal Protocols
Generic Transmission Limits (GTLs) associated with GTCs are posted on the MIS Secure Area
The need for GTC is typically identified to manage stability, voltage, and other constraints that cannot otherwise be modeled directly in ERCOT’s powerflow and contingency analysis applications.

12. GTCs Implemented in ERCOT in 2015
The Zorillo to Ajo GTC has been effective since February 27, 2015
The Panhandle GTC has been effective since July 31, 2015
The Laredo GTC has been effective since September 9, 2015
The Liston GTC is effective starting November 12, 2015
The Molina GTC is effective as of December 01, 2015

13. Location of the GTCs

14. Future Generators (MW) with SGIA
* Based on GINR information as of November 12, 2015

15. From Station (Acronym)
Zorillo to Ajo GTC
The Zorillo to Ajo GTC constraint limits the flow on the Zorillo – Ajo 345 kV line:
The constraint represents a stability limit associated with coastal wind farms connecting to the Ajo substation
The instability includes undamped and high magnitude oscillations during high generation output following a three phase to ground fault event
The interface name associated with this GTC in the Network Operations Model is “ZO_AJO”
Line Acronym
From Station (Acronym)
To Station (Acronym)
Voltage Rating (kV)
Line Rating (MVA)
AJO_ZORILL1
Ajo (AJO)
Zorillo (ZORILLO)
345
1852*
* Line is dynamically rated. Listed rating is static nominal rating.

16. From Station (Acronym)
Panhandle GTC
The Panhandle GTC is an interface constraint consisting of the following transmission lines:
The constraint represents a voltage stability limit associated with flows out of the Panhandle area
The interface name associated with this GTC in the Network Operations Model is “PNHNDL”
Line Acronym
From Station (Acronym)
To Station (Acronym)
Voltage Rating (kV)
Line Rating (MVA)
RILEY_TESLA1
Tesla (TESLA)
Riley (RILEY)
345
2988*
JIMTRE_TESLA2
Jim Treece (JIMTREEC)
EDITHC_TESLA1
Edith Clarke (EDITHCLA)
EDITHC_TESLA2
COTTON_EDITHC3
Cottonwood (W_CW_345)
COTTON_EDITHC4
T-301
Dermott Switch (DMTSW)
1792**
T-302
* Line is dynamically rated. Listed rating is static nominal rating.
** Line is dynamically rated and jointly owned; most limiting static nominal rating is provided

17. From Station (Acronym)
Laredo GTC
The Laredo GTC is an interface constraint consisting of the following transmission lines:
The constraint represents a voltage stability limit associated with flows into the Laredo area
The interface name associated with this GTC in the Network Operations Model is “LAREDO”
Line Acronym
From Station (Acronym)
To Station (Acronym)
Voltage Rating (kV)
Line Rating (MVA)
LOBO_SANMGS1
San Miguel (SANMIGL)
Lobo (LOBO)
345
1793
HOLCOM_NLARSW1
Holcomb (HOLCOMB)
North Laredo Switch (NLARSW)
138
177*
NLARSW_PILONC1
Piloncillo (PILONCIL)
122
LAQUIN_LOBO1
La Quinta (LAQUINTA)
347*
JAVALT_MOLINA1
Javalina Tap (JAVALTAP)
Molina (MOLINA)
257*
FREER_LOBO1
Freer (FREER) 69 38
* Line is dynamically rated. Listed rating is static nominal rating.

18. From Station (Acronym)
Liston GTC
The Liston GTC is an interface constraint consisting of the following transmission lines :
The constraint represents a control instability limit associated with generators in the Liston area
The interface name associated with this GTC in the Network Operations Model is “LISTON”
Line Acronym
From Station (Acronym)
To Station (Acronym)
Voltage Rating (kV)
Line Rating (MVA)
BATES_LISTON1
Liston (LISTON)
Bates (BATES)
138
257*
GARZA_MIGHOW1
Mighoward Tap (MIGHOWTP)
Garza (GARZA)
* Line is dynamically rated. Listed rating is static nominal rating.

19. From Station (Acronym)
Molina GTC
The Molina GTC constraint limits the flow on the Aguilare – Javalina 138 kV line:
The constraint represents a control instability limit associated with generators in the Molina area
The interface name associated with this GTC in the Network Operations Model is “MOLINA”
Line Acronym
From Station (Acronym)
To Station (Acronym)
Voltage Rating (kV)
Line Rating (MVA)
AGUILAR_JAVLTP
Aguilare (AGUILAR)
Javalina Tap (JAVALTAP)
138
251*
* Line is dynamically rated and jointly owned; most limiting static nominal rating is provided

20. Objectives
Identify the new generation coming into ERCOT grid in the next 18 months
Identify newly implemented Generic Transmission Constraints (GTC) in ERCOT system
Identify remaining reliability issues that potentially require Constraint Management Plans (CMP) for 2016
Identify major 345-kV projects expected to be in-service from April 2016 to September 2017
Recognize future system issues identified and studies being done for the Valley and Houston areas

21. How Power Outages Might Occur
Snakes, birds, trees, equipment failure, storms, people...
It is necessary to plan ahead to make the grid as strong as possible well before a series of events occur that could trigger an emergency.
For example, this event occurred in July, 2014 in Massachusetts:

22. Hot Air Balloon Hits Power Line

23. 2015 Regional Transmission Plan (RTP)
The RTP is ERCOT’s annual transmission assessment to identify transmission needs over the next six years
ERCOT staff coordinates the planning activities with ERCOT’s Regional Planning Group (RPG) and the Transmission Planners (TPs)
Identify Corrective Action Plans such as Reliability projects and Constraint Management Plans (CMPs) in accordance with NERC Reliability Standards and ERCOT reliability criteria
Identify Economic projects per the ERCOT Economic Planning Criteria

24. 2015 RTP – Potential CMPs
Some reliability issues were not mitigated with projects
Project may have had construction delays
Recent system changes such as new loads
Mostly 69kV constraints
Mostly 2016 Summer
Constraint Management Plan
Operational actions to resolve transmission security violations
Includes Mitigation Plans, Pre-Contingency Action Plans, Remedial Action Plans, and Temporary Outage Action Plans
RTP identifies potential CMPs with input from TPs
Operations Planning will consider the potential CMPs when finalizing the list of CMPs for 2016

25. 2015 RTP – Potential CMPs
This list contains only those CMPs involving single circuit or common structure contingencies

26. 2015 RTP – Potential CMPs

27. Objectives
Identify the new generation coming into ERCOT grid in the next 18 months
Identify newly implemented Generic Transmission Constraints (GTC) in ERCOT system
Identify remaining reliability issues that potentially require Constraint Management Plans (CMP) for 2016
Identify major 345-kV projects expected to be in-service from April 2016 to September 2017
Recognize future system issues identified and studies being done for the Valley and Houston areas

28. 345-kV Projects Under Construction
As projects are planned and constructed, Transmission Service Providers (TSPs) provide transmission data to ERCOT via a web-based modeling application (Model on Demand)
Projected In-Service Dates are included in the data
This data can be used to update models and also to develop a list of projects that are expected to be In-Service for a given timeframe (in this case, the next 18 months)
Major 345-kV projects such as new lines and transformers were included in the compiled list, while other projects such as transformer replacements, terminal upgrades, or reactors are not

29. 345-kV Projects Under Construction
* Based on project tracking information as of October 1, 2015

30. 345-kV Projects Under Construction

31. Objectives
Identify the new generation coming into ERCOT grid in the next 18 months
Identify newly implemented Generic Transmission Constraints (GTC) in ERCOT system
Identify remaining reliability issues that potentially require Constraint Management Plans (CMP) for 2016
Identify major 345-kV projects expected to be in-service from April 2016 to September 2017
Recognize future system issues identified and studies being done for the Valley and Houston areas

32. Lower Rio Grande Valley (LRGV) Study
Add Lobo - North Edinburg - Loma Alta 345-kV lines (June 2016)
The entire Frontera Facility will not be available to ERCOT after the Lobo - North Edinburg - Loma Alta lines are energized (2016)
Legend
Existing 345kV line
Existing substation
In progress 345kV line
Proposed 345kV line
Proposed 345kV sub
Proposed 345kV xfr
Proposed SVC

33. Lower Rio Grande Valley (LRGV) Study
2021 Summer Peak
Load: ,752 MW
Nat gas gen: 1,470 MW
Reliability Violations included a voltage stability limitation during contingencies involving generation near the North Edinburg sub
Transmission projects submitted to ERCOT’s RPG
April 16, 2015: American Electric Power Service Corporation (AEPSC)
September 15, 2015: CPS Energy and Sharyland
ERCOT is expecting to complete studies by March 25, 2016

34. Lower Rio Grande Valley (LRGV) Study
AEPSC Recommendation: North Hill – Ajo – Zia 345-kV Lines (≈125 miles) & 3 Static VAR Compensators (SVCs). $621.5 Million
North Hill
Zia
Legend
Existing 345kV line
Existing substation
In progress 345kV line
Proposed 345kV line
Proposed 345kV sub
Proposed 345kV xfr
Proposed SVC

35. Lower Rio Grande Valley (LRGV) Study
CPS Energy/Sharyland Recommended Solution: Elm Creek - Palmito dbl ckt 345kV lines (≈280 miles), La Palma - Palmito 345kV line (≈30 miles), multiple 345-kV transformers, SVCs, etc. $ Million
Legend
Existing 345kV line
Existing substation
In progress 345kV line
Proposed 345kV line
Proposed 345kV sub
Proposed 345kV xfr
Proposed SVC

36. AEPSC Hidalgo-Starr Study
Significant load growth in Hidalgo County which is served through various 138-kV circuits
Thermal violations observed on the 138-kV system for various contingencies in the 2017 and 2020 Summer Peak study years
Transmission expansion project submitted to ERCOT’s RPG
July 13, 2015: AEPSC Hidalgo-Starr Transmission Project
AEPSC Recommended Solution
Cut Stewart Road substation into N.Edinburg – Loma Alta 345-kV line (≈10 miles)
Add two 345/138-kV transformers at Stewart Road
Add Pomelo – Frontera 345-kV line (≈23 miles)
Add 345/138-kV transformer at Frontera
Split and reconfigure 138-kV lines at locations including West Edinburg and Pharr
Perform related substation construction
$151 Million
In Service Date: TBD

37. AEPSC Hidalgo-Starr Study
The 345-kV system may be extended into the Frontera and Stewart Rd substations.
Legend
Existing 345kV line
Existing substation
In progress 345kV line
Proposed 345kV line
Proposed 345kV sub
Proposed 345kV xfr
Proposed SVC
Pomelo
Stewart Rd

38. Houston Import Project
ERCOT has determined that there will be a need for additional import capacity into the Houston region by 2018
Population in the Houston region is expected to grow at a rate of over 100,000 new residents per year
The Houston metro area has almost 40% of the nation’s petrochemical manufacturing capacity
The Port of Houston has ranked first among U.S. seaports in terms of import tonnage for 22 consecutive years
The Houston region represents approximately ¼ of the total ERCOT peak system load

39. Houston Import Project
Transmission Projects were submitted to the RPG in 2013
ERCOT planning criteria violations occurred in the 2018 peak load case
The Singleton-Zenith 345-kV lines were overloaded under N-1
Multiple 345-kV lines were overloaded and there were low voltage conditions under G-1 and N-1

40. Houston Import Project
ERCOT evaluated 21 project alternatives
The study included:
Power Transfer Analysis
Production Cost Savings analysis
In 2014, the ERCOT Board of Directors (BOD) endorsed the recommended solution:
Limestone – Gibbons Creek – Zenith double circuit 345-kV lines (≈130 miles)

41. Jones Creek Project
Freeport LNG Development, Limited Partnership announced a natural gas liquefaction and export project on Quintana Island
690 MW total load (no self-serve generation)
Additional 146 MW load with 82 MW self-serve generation at pretreatment plant (not on Quintana Island)
Load will come on between Q and Q3 2018
Transmission expansion project submitted to ERCOT’s Regional Planning Group
July 2014: CenterPoint Energy submitted a project proposal to the RPG that includes new Jones Creek 345/138-kV station and multiple 138-kV system upgrades in the Freeport area

42. Jones Creek Project
Planning criteria violations occurred at 2019 peak load levels
The Freeport – Quintana - Surfside 138-kV lines were overloaded under N-1
There was voltage collapse during under X-1 and N-1 (Both Dow 345/138-kV transformers outaged)

43. Jones Creek Project
In February 2015, the ERCOT BOD endorsed this solution:
Construct a new 345/138-kV Jones Creek Substation
Install two new 345/138-kV transformers at Jones Creek
Split/reconfigure/upgrade multiple 138-kV facilities
$77.8 Million. In-service May 2017
Jones Creek

44. Questions ?

45. Objectives
Identify the new generation coming into ERCOT grid in the next 18 months
Identify newly implemented Generic Transmission Constraints (GTC) in ERCOT system
Identify remaining reliability issues that potentially require Constraint Management Plans (CMP) for 2016
Identify major 345-kV projects expected to be in-service from April 2016 to September 2017
Recognize future system issues identified and studies being done for the Valley and Houston areas