March 14, 2014
Mr. Tracy Rolstad, Chair
WECC Technical Studies Subcommittee
Avista Corp.
1411 East Mission Avenue
Spokane, WA 99220-3727
Mr. Enoch Davies
Staff Engineer
Western Electricity Coordinating Council
155 North 400 West, Suite 200
Salt Lake City, Utah 84103-1114
2014 Annual Progress Report
Tri-State Generation and Transmission Association
In accordance with WECC reporting requirements, the following Annual Progress Report is submitted by
Tri-State Generation and Transmission Association. This report includes updates to previously reported
projects, initial progress reports for new projects, and descriptions of projects for which Tri-State
requests waivers of Significant Project Status.
Wayne Child Substation Project (aka TOT 3 Archer Interconnection Project)
This Project will construct a new substation (Wayne Child substation) which will sectionalize MBPP’s
Laramie River Station (LRS) – Story 345 kV line near the existing Archer substation, complete with
345/230 kV transformation, and construct approximately 1/3-mile of 230 kV line between Archer and
Wayne Child substations. Line upgrades of the LRS – Ault and LRS – Wayne Child 345 kV lines will be
necessary, as well as capacitors at Dalton substation near Sidney. This project will also establish a 34.5
kV point of delivery for High West Energy’s proposed 34.5-12.5 kV, 20 MVA substation contained within
Tri-State’s proposed Wayne Child 345-230 kV substation. The project is planned to be completed in the
4th quarter, 2017, and is in Phase III of the WECC Three Phase Rating Process.
Lamar-Front Range Project
This project includes two high voltage transmission paths, one from Lamar substation to Pueblo area
and a second from Lamar to substations near Brush and/or Deer Trail. This will provide for better
reliability to serve loads in the entire eastern Colorado footprint. Multiple voltage options have been
examined. This project will be built in stages, with each designated stage being a part of the overall plan
to address the eastern Colorado transmission needs. This project will also provide the infrastructure for
Xcel Energy to meet Colorado Senate Bill 07-100 requirements by connecting several Energy Resource
Zones in eastern Colorado to the Denver Front Range area.
Burlington-Lamar 345/230 kV Project (Request for Waiver 2014)
The purpose of Burlington-Lamar Transmission Project is to incrementally alleviate existing and
future transmission system constraints in southeast and eastern Colorado as identified in the
Lamar Front Range studies. It is a subset of the greater Lamar Front Range project. To
accommodate future build outs, the Burlington-Lamar line may be constructed for 345 kV
operation, but will initially be operated at 230 kV.
Badwater-Casper 230 kV Line Project
This project involves constructing a new 230 kV transmission line from Casper substation to Badwater
(PACE) substation. The new 70 mile long line will allow improved reliability and allow Tri-State to serve
new load near central Wyoming. The planned in-service date is expected to be in 2018.
Keota 345/115 kV Project
This project involves sectionalizing the Laramie River Station (LRS)-Story 345 kV line for a load serving
connection approximately 60-65 miles northwest of Story. Tri-State would install a 225 MVA, 345/115
kV transformer at Keota substation, with the possible future addition of a second transformer. The level
of load planned for this substation is initially 40 MW, with a potential increase to 120 MW based on the
most recent load connection requests. The planned in-service date is 2015. This project is in Phase III of
the WECC Three Phase Rating Process.
Boone-Walsenburg 230 kV Line Project (2013 Waiver Granted)
The Boone-Walsenburg project will consist of one new 230 kV transmission path from the existing
Boone substation, owned by Tri-State and Xcel Energy, to the existing Walsenburg substation, owned by
Tri-State. The conductor will be 1272 MCM ACSR-Bittern with a maximum design temperature of 100°C
and be owned by Tri-State. Addition of a new 230 kV line will increase reliability in the Pueblo, Colorado
area and also in Northeast New Mexico. Presently, the loss of the Comanche-Walsenburg 230 kV line
results in severe thermal overloading on the 115 kV transmission system from West Station to
Walsenburg. In order to mitigate the overloading, a Remedial Action Scheme (RAS) trips the
Walsenburg-Gladstone 230 kV line which results in the loss of load and reduced reliability in Northeast
New Mexico. The planned in-service date is 2018.
San Juan Basin Energy Connect Project (2013 Waiver Granted)
This project involves constructing a new 230 kV transmission line between the existing WAPA Shiprock
Substation in New Mexico and a new 230 kV Iron Horse Substation in southwestern Colorado. A new
230 kV Kiffen Canyon Substation will also be required along with a phase shifting transformer. It will
allow Tri-State to serve approximately 100 MW of new industrial load in SW Colorado.
San Luis Valley-Carson 230 kV Line Project (aka San Luis Valley-Calumet-Comanche
Transmission Project)
This project consists of a new 230 kV transmission line from the existing San Luis Valley substation to a
new Carson 230/345 kV substation located west of Taos NM. The Carson 230/345 kV substation will tap
the existing Taos-Ojo 345 kV line and will include 230/345 kV transformation and a 230 KV phase shifting
transformer. The planned in-service date for this project is 2022.
Montrose-Nucla-Cahone Transmission Upgrades (aka Western Colorado Transmission
Upgrade Project) (2013 Waiver Granted)
This project upgrades the existing transmission lines and facilities from Montrose substation to Cahone
substation from 115 kV operation to 230 kV. The purpose of this project is to improve system reliability
by eliminating the Nucla Remedial Action Scheme. The planned in-service date for this project is 2019.
Burlington-Wray 230 kV Line Project (2012 Waiver Granted)
The Burlington-Wray 230 kV Line Project is intended to increase reliability in the project area, remove
restrictions on the Burlington area network resources, and increase the deliverability of Tri-State
resources to Tri-State member loads. This will be accomplished by adding a new 230 kV line from the
Burlington substation to the Wray substation. The addition of the 230 kV line will add one new
transmission line segment that will be constructed as a single circuit using 1272 MCM ACSR conductor
with a maximum operating capacity of 1538 amps. This additional capacity will alleviate congestion in
the Burlington area, increase reliability, and allow the potential development of renewable generation
resources in the Burlington and Wray areas which currently have existing wind resources. The planned
in-service date is 2016.
Big Sandy-Calhan 230 kV Line Project (2012 Waiver Granted)
The primary purposes of the Big Sandy -Calhan 230 kV project are threefold: mitigate the projected
overloads of Tri-State’s 100 MVA 230-115 kV Fuller transformer, should other mitigating actions not
take place; increase Tri- State’s ability to deliver resources to Mountain View Electric Association (MVEA)
and its other southeastern Colorado members; and provide a bulk transmission connection (i.e., a
"strong" voltage source and increased power transfer capacity) to the eastern side of MVEA’s service
area. This will be accomplished by adding a 230 kV line from Big Sandy substation to a new Calhan
substation. This project is presently planned to be in-service 2019.
Gladstone 230 kV Phase Shifting Transformer Project (2012 Waiver Granted)
The project is to add a 300 MVA Phase Shifting Transformer (PST) at the Gladstone existing substation.
Studies by Tri-State and others have all shown the need for transmission network upgrades in the North
East New Mexico (NENM) area to improve system reliability, load serving capability, mitigate operating
issues related to phase angle differences, and to reduce system losses. The planned in-service date for
this project is 2018.
J.M. Shafer-Henry Lake 230 kV Project (Request for Waiver 2014)
Tri-State’s J.M. Shafer generating station has a total capacity of 272 MW and has some capability to be
upgraded in the future. The station presently relies on the 230kV Fort Lupton Substation and its
interconnected transmission system owned by Xcel Energy to deliver power to Tri-State’s loads in the
PSCo Balancing Authority area. Since Tri-State has load in both the PSCo Balancing Authority area and
the WACM Balancing Authority area, Tri-State desires the flexibility to directly deliver the output of the
J.M. Shafer station to either Balancing Authority. Tri-State can do so by interconnecting the J.M. Shafer
station directly to the Greenhouse Substation and constructing a Greenhouse to Henry Lake 230 kV line.
Tri-State forecasts an increasing need for additional balancing resources in the WACM BA to comply
with the State of Colorado’s Renewal Portfolio Standards. The J.M. Shafer to Greenhouse to Henry Lake
230kV project will permit Tri-State to utilize the J.M. Shafer station as a balancing resource in the WACM
BA. The project will also improve transmission reliability by providing a second transmission source
directly to the J.M. Shafer station and mitigates the problem of losing the entire station for a single line
outage.
Santa Rosa-Gladstone 230 kV Tie Line Project
This project has been cancelled.