rHE rExas connvccTiorv
July 13, 2009
LCRA Transmission Services Corporation
3700 Lake Austin Blvd.
Austin, Texas 78767
Attn.: Sergio Garza, P.E.
Manager, System Planning and Protection
Mr. Garza:
ERCOT has reviewed and analyzed the engineering specifications for LCRA's proposed change to the
endpoint of the Gillespie-Kendall transmission line included in the CREZ Transmission Optimization
(CTO) Study filed by ERCOT in Public Utility Commission of Texas (PUCT) Docket No. 33572. In the CTO
Study, the subject line was specified as a new 345-kV right-of--way (ROW) connecting the Gillespie
substation to the 345-kV Kendall substation. Following completion of the CTO Study, LCRA proposed
changing this line's endpoint from the Kendall substation to a proposed West Wind substation located
north of Kerrville near the border between Kerr County and Gillespie County. LCRA states the purpose
of this proposed modification is to utilize an existing ROW for the new345-kV circuit.
ERCOT has determined that LCRA's proposed change would result in addiYronal congestion around the
Gillespie substation, which would reduce the overall effectiveness of the CREZ Transmission Plan (CTP)
and, therefore, would not be consistent with the CTO Study. To mitigate the increased congestion that
would result under LCRA's proposal, the following additional system upgrades would be required:
1. The addition of a second 600-MVA 345/138-kV autotransformer at the Gillespie substation;
2. The upgrade of the 138-kV transmission line from Gillespie to Fredericksburg to Kendall from a
220-MVA rating to a 507-MVA rating; and,
3. The upgrade of the 138-kV transmission line from Gillespie to Wolf Creek to Kerrville from a
220-MVA rating to a 507-MVA rating.
LCRA informed ERCOT that changing the line's end-point from the Kendall substation to the West Wind
substation would save approximately $11 million. LCRA, however, determined that the three additional
system upgrades listed above would cost approximately $34 million. Thus, LCRA's proposal reflects a
net increase of $23 million relative to the cost associated with utilizing the Kendall substation as
described in the CTO Plan.
~° Taylor
7620 Metro Center Drive 2705 WESt lakE DNve
Austin, Texas 78744
Td. 512.225.7000 I Fax 512.225.7020
Taylor; Texas 76574
Td. 512.248.3000 I Fax 512.248.3095
Based on the impacts described above, ERCOT does not recommend LCRA's proposal to change the
endpoint of the Gillespie -Kendall transmission line from the Kendall Substation to the proposed West
Wind substation, because it is neither cost-effective nor consistent with the CTO Study.
Please contact me if you have any questions.
Sincerely,
~ ~'~
Warren t.asher
Manager, System Assessment