Groundbreaking for New Hydroelectric Plant Coming Soon
OURAY COUNTY – The Ridgway Dam was designed with hydropower in mind, but it wasn't until recently that hydropower became a feasible project for the Tri-County Water Conservancy District.
In about a month, district officials are hopeful they it will be able to break ground on the project, which, upon completion, will create about $1 million annually in revenues and produce enough electricity for 3,000 houses each year.
The 8-megawatt project will contain two turbines and two generators — a 1.8-mw system that will operate in the winter months during lower flows, and a 7.2-mw system for the higher-flow irrigation months.
"Winter flows are significantly less than our summer flows, and we can't get a generator that would operate efficiently for that wide range," Tri-County Water General Manager Mike Berry said.
The two different systems, both of which can operate during peak flows, is the most efficient method of capturing energy from the dam, he said.
Tri-County Water has gone through the necessary steps to get the project underway, and is now waiting for the completion of just two items before construction begins: the design plans need final approval from the Bureau of Reclamation, and interconnection agreement — to allow the power that's captured to be transferred onto the grid — must be reached between Tri-County Water and Tri-State Generation and Transmission.
Tri-State is the wholesale power provider for area electrical providers, including Delta-Montrose Electric Cooperative and San Miguel Power Association, and brokering an agreement with Tri-County Water has been a lengthy and expensive process, Berry said.
In April 2011, Tri-County Water completed its environmental assessment for the project, and by the end of 2011, the official Finding of No Significant Impact report was released. In February of this year, the district was awarded a Lease of Power Privilege from the Bureau of Reclamation to develop the hydropower resources. Since that time, Tri-County Water has secured funding to pay for the project, and has entered into agreements to sell that power.
The City of Aspen has agreed to purchase power produced in the winter – about 40 percent of the total hydropower produced – while Tri-State Generation and Transmission will purchase the other 60 percent that is produced, during the rest of the year, Berry said.
Phil Overeynder, utilities engineer and former utilities director for the City of Aspen, said his city council was pushing staff to find more sources of alternative power when he came across the 1984 feasibility report on the Ridgway Dam hydropower project, and approached the district. Aspen had already invested in two other hydropower plants and knew the advantages of a fixed-cost electricity source, he said.
"We saw that benefit and wanted to be part of this project," Overeynder said.
Several feasibilities studies were done on the potential of hydropower generation at the dam over the years, but it wasn't until now, with low interest rates and a source to sell the power to, that the pieces for the project came together.
Tri-County Water was able to obtain a 30-year loan from the Colorado Water Conservation Board for about $9 million, and then another $2 million, 20-year loan from Colorado Water Resources and Power Development Authority, both at a 2 percent interest rate, Berry said. Tri-County Water has committed to providing about $4 to $5 million of its own money toward the project, which it expects will pay off in about seven to eight years, he said.
The district has factored in such costs as debt payments, maintenance expenses and capital reserves to come up with an annual budget, but until the entire project is complete, exact numbers won't be available, as the project could cost anywhere from $14 to $17 million, he said.
Of the total cost, about $11.5 million will go to pay the project’s contractor, Mountain States Hydro, of Idaho.
Once the final documents and agreements are in place, Mountain States Hydro will begin building the power house at the base of the dam, and put in the proper piping and construct the small turbine. The company is hopeful that the small turbine will be operational by this time next year. The large turbine will be assembled during the winter of 2013-14, and should be operational by the spring of 2014.
As part of the new design at the dam, the energy that is currently being pumped into the river from the dam – causing a super-saturation of nitrogen into the water and affecting the fish – will be eliminated, because the water will be slowed as it moves through the turbines.
"We will take that energy that is causing that condition and make electricity out of it," Berry said.
Kati O'Hare at kohare@watchnewspapers.com or Tweet @katiohare
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