Tri-State: power line would blow away constraints on wind generation

The planned Burlington–Lamar 230 kV Transmission Line Project will, among other things, provide a critical path for new wind generation in eastern Colorado, said Tri-State Generation and Transmission Assn.

Tri-State on Feb. 6 applied at the Colorado Public Utilities Commission for a certificate of public convenience and necessity on this power line. Among those supplying supporting testimony was Christopher E. Pink, Tri-State’s Manager, Technical Services/Bulk System Planning.

This project is a new single-circuit, 230 kV transmission line interconnecting the existing Burlington and Lamar substations. The new transmission line will be 90-110 miles long. The project will be located in Kit Carson, Cheyenne, Kiowa, and Prowers counties and will cross areas served by Tri-State Member Systems K.C. Electric Association and Southeast Colorado Power Association.

“The Burlington system is generation rich and transmission constrained,” Pink wrote. “The most significant issue is its ability to safely export power following an outage of the Burlington–Big Sandy–Lincoln–Midway 230 kV system. During periods of high generation, significant overloads on the underlying 115 kV network occur following 230 kV outages. This condition is exacerbated during low-load, high-wind conditions.

“To ensure 115 kV overloads do not occur, the Burlington area generation is restricted through operating procedures and agreements. This situation presently restricts any new renewable generation in the Burlington area. The future Burlington–Wray 230 kV project significantly relieves these restrictions. It does not, however, provide sufficient relief to accommodate all planned future generation. For example, Tri-State has plans for a 150 MW network resource, named Carousel Wind, to be connected at Burlington 230 kV in 2015. Lacking a significant transmission project, the output of Carousel Wind will be limited during light load conditions to protect against 230 kV outages, much like today’s existing Burlington area generation.

“The Project provides increased operational flexibility for maintenance outages, better transmission system performance following multiple contingencies, reduced regional losses, and more stable voltages across a wide range of system conditions. The Project also increases transmission capacity in regions with a high potential  for new wind resources. This benefits stakeholders developing such projects, supports public policy goals (e.g., SB13-252), and possibly increases competition, thereby providing Tri-State a more diverse portfolio of generation resources from which to choose. Another benefit is that a new Burlington–Lamar transmission element aligns with other major, strategic transmission projects in the region. Constructing the Project is an important first step to ultimately meet some of the objectives of these larger transmission projects.”

Pink later added: “Tri-State has studied various scenarios in eastern Colorado, including increased Lamar injection levels from 608 MW to 780 MW. In each of these scenarios, a new 230 kV transmission element between Burlington and Lamar was a critical first piece of any final build-out. Other elements could include increased transmission between Lamar and Comanche and Burlington and Big Sandy. In summary, the Burlington–Lamar 230 kV line aligns with, and is the appropriate first step for most reasonable transmission build-out scenarios for eastern Colorado.”

The estimated cost of the project is $72.6m. It is scheduled to begin construction in 2019, be completed in 2020 and have an in-service date by the end of 2020.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.