Tri-State is moving closer to receiving its permit to begin construction of the interconnection station and transmission lines from the Tri-County Water Hydropower Project located at Ridgway Reservoir (Ouray County, Colo.), with approval of the Bureau of Reclamation’s recently drafted environmental assessment of the plant site in view.
The association hopes to begin construction in June and finish the Ridgway Dam Substation by November or December of this year — months ahead of the original schedule — and enter into a 10-year power purchase agreement (PPA) with the Tri-County Water Conservancy District.
“The unique aspect of this project is that the water district will have two PPAs for the electricity produced at the site,” said Brad Nebergall, Tri-State’s senior vice president of energy management. “For eight months of the year the power will be sold to the city of Aspen and for the other four months — June through September — the plant’s output will be sold to Tri-State,” he said.
Tri-State’s summertime portion of the generation is projected to be about 60 percent of the hydro plant’s annual energy output, according to Nebergall.
The 8-megawatt hydro facility is located within Tri-State’s member system San Miguel Power Association’s (Nucla, Colo.), service territory and, as such, will receive station electric service from the co-op. The facility will connect to a nearby existing 115-kV transmission line that is scheduled to be transferred in 2014 from San Miguel Power to Tri-State ownership under the ongoing Board Policy 109 asset transfer program.
Annual output of the Ridgway plant is estimated to be 24 gigawatt-hours during average water years. The project, comprised of two generators — a larger 7.2 megawatt unit and an 800-kilowatt unit — is being developed and operated by the water conservancy district under a Lease of Power Privilege arrangement with the U.S. Bureau of Reclamation.