Beginning in 2015, Tri-State has contracted for the output from its first hydroelectric resource from Wyoming – adding to its growing renewable portfolio that now comprises approximately 20 percent of the energy that the association provides to its 44 member systems. Completed in 1983, the Garland Canal Hydroelectric Project is located in northwest Wyoming, within the service territory of Tri-State member, Garland Light & Power (Powell, Wyo.). The 2.9-megawatt hydroelectric plant is owned and operated by the Shoshone Irrigation District, which provides water to approximately 1,200 farmers and ranchers over about 36,000 acres of farmland near Powell. It is a part of the U.S. Bureau of Reclamation’s (USBR) Shoshone Project, which is comprised of a series of dams that divert water from the Shoshone River into multiple irrigation canals that serve the project.
The generating plant is sited on the Garland Canal, at a point near the town of Ralston. The canal drops about 50 feet in elevation over a distance of less than half a mile through the Ralston Chute, after which, the rushing water flows through the powerhouse to generate electricity. The turbine/generator produces an average annual output of 10 million kilowatt-hours. The plant was originally financed for $1.5 million under a U.S. Department of Energy grant as a small-scale hydroelectric power demonstration project.
Water for the project originates from the USBR’s 646,000-acre-feet Buffalo Bill Reservoir, located west of Cody, Wyo. The availability of this large water resource provides a stable, drought-resistant water supply to the Garland Canal Hydroelectric Project.
Tri-State’s 10-year contract to purchase the project output and associated environmental attributes began on Jan. 1, however, as with most irrigation-related projects, hydro-generation will occur between mid-April and mid-October, according to Susan Hunter, Tri-State’s business development manager for energy resources.