1. Barrilla Junction Area Transmission Improvements Project
ERCOT Regional Planning Group
March 22nd. 2016
(Prepared by AEPSC)

3. One line of the existing Barrilla Junction
Area transmission system with future loads

4. Study Drivers
New Direct interconnection load requests and increased load forecast at existing points of delivery
Increased solar generation interconnections in the area
Maintain NERC, ERCOT, Oncor and AEP reliability criteria
Bus Name
Bus Number
2016
2017
2018
2019
2020
Pig Creek
38375
25.00
County Road 101
6657
24.60
34.30
36.80
37.40
Gas Pad
11112
21.90
Musquiz
38305
15.38
27.50
28.90
34.20
34.10
Lotebush
6656
0.00
5.75
23.33
23.41
Hackberry Draw
38370
6.64
 Total
86.88
114.45
133.43
141.31
141.81

5. Study Methodology Case preparation
West Texas Study 2020 case modified with the latest load projections from customer requests
Dispatch assumption given flows on the north and east of Barrilla Junction are heavily impacted by the generation at Permian Basin, Barrilla Junction and Ft. Stockton
Study zone comprised of the West and Far West zones
Branch loading and bus voltages monitored for 69 kV and above facilities
Contingency events
Contingency
Event
NERC Event
Description
N-0 P0
System normal, Zero elements out of service.
N-1 P1
Forced outage of a single Transmission line, Transformer, Generating unit, Common tower outage, Shunt or FACTS device.
N-G-1 P3
Loss of a generating unit followed by an N-1 event defined above.

6. Study Methodology Generation Dispatch Assumptions
In the Low Wind (LW) dispatch, all the area wind generators were dispatched at 20% with the exception of the two Woodward units that were dispatched to 0%.
In the High Wind (HW) dispatch, all area wind generators including the Woodward units were dispatched at 100% of Pmax.
In the Low Solar (LS) dispatch, all the solar generators in the study area were dispatched to 0%.
In the High Solar (HS) dispatch, all solar generators in the study area were dispatched at 100% of Pmax.
In the Low Gas (LG) dispatch, all the area gas generators were dispatched at 20% with the exception of the Permian gas units that were dispatched at 0%.
In the High Gas (HG) dispatch, all the area gas generators were dispatched at 100% of Pmax.
2020 HS/LW/HG
2020 HS/HW/LG
2020 LS/LW/LG
2020 LS/LW/HG
Solar
100% 0%
Wind
20%
Woodward
Gas
Permian

7. Existing System Performance
Existing system cannot support the projected load growth in the area and the export of renewable (solar) generation outside the area
Most Limiting Contingency:
Loss of either end of the line
System Limitation:
Post Contingency Voltages in the Barrilla Junction area drop below 0.92 p.u.
Overload of the existing line beyond emergency rating
Reasons Why Additional Facilities Will Be Required By Jan. 2020
Load connecting to Permian Basin – Barrilla Junction line is projected to be at 150 MW
Solar generation requests in the area – 1,950 MW
Improvements are Required to Maintain NERC Compliance

8. One line of the existing Barrilla Junction
Area transmission system showing
overloaded facilities

9. AEP and Oncor Recommendation
Recommended Solution:
Rebuild the existing Barrilla Junction/Solstice to Permian Basin AEP-TNC/Oncor 138 kV transmission line – approximately 54 miles
Hackberry Tap (Lotebush)– Build a new station near the existing tap location and install a dynamic reactive device.
Ft. Stockton Plant – Rebuild existing Ft. Stockton plant to a multi bus configuration and install dynamic reactive device.
Benefits:
Improves Load Serving Capability of the Permian Basin – Barrilla Junction 138 kV line
Relieves congestion in the Barrilla Junction Area
Recommended in the 2015 RTP plan and passed the economic test
Estimated Cost: $ M

10. Rebuild Solstice to Permian Basin 138 kV
Lotebush/Hackberry Tap – Add dynamic reactive device
Rebuild Solstice to Permian Basin 138 kV
Pig Creek
Rio Pecos
Barrilla Junction / Solstice
Ft. Stockton Plant- Add dynamic reactive device

11. One line of the Barrilla Junction
Area Transmission System Improvements