RIDGWAY – For decades the Ridgway Dam’s pent-up power production potential has gone unrealized. Now, that is about to change.
Over the past year and a half, two hydropower generators have sprung up at the foot of the dam: a smaller, 800kV generator that should run efficiently on the low, 30-60 cubic-feet-per-second flows in winter, and a larger, 7.2 megawatt generator to run on summertime release levels.
Next week, on Feb. 24 or 25, the smaller of these two units will be turned on and start producing a steady stream of green electricity, said Mike Berry of Tri-County Water Conservation District, the entity that manages the Ridgway dam and is building the power-generating facility at its base.
The big generator should be ready for testing by April or so, Berry said. When the project goes fully online later this spring or early summer, it will have a total plant capacity of 8 Megawatts – enough renewable power to run 2,250 homes and take the equivalent, in greenhouse gases, of 4,400 cars off the road.
Both units will operate during high reservoir releases in the summer, and only the smaller unit will operate during lower wintertime releases.
Tri-State Generation and Transmission, the wholesale electric supplier for San Miguel Power Association and the Delta-Montrose Electric Association, has built two short transmission lines at the hydropower plant. One will connect to the existing 115kV line running alongside the highway, and another will connect with the generating station.
Power generation will have to be carefully calibrated in order to maintain historic release patterns at the dam – one of the requirements of the Bureau of Reclamation’s final Environmental Assessment of the project – while maintaining healthy lake levels and maximizing power production.
In times of drought, the water rights of downstream irrigators, industries and municipalities will trump power generation.
“I am told these machines have what they call sweet spots, and we are going to try to discover what those sweet spots are of each machine, and target release around the sweet spots to maximize power generation and minimize wear and tear,” Berry said. “It’s a trial and error thing up front, but sooner or later we hope to have it dialed in.”
Power generated at the hydro plant will be sold to two entities: Tri-State, and the City of Aspen. Tri-County WCD first started discussing a partnership with the City of Aspen in 2002. Eventually, this partnership evolved into a Power Purchase Agreement, or PPA.
In an agreement inked in 2010, Aspen agreed to purchase the wintertime output from the hydropower project, from Oct. 1 through May 31, for 20 years, to help further its goal of powering the city with purely renewable energy. Tri-State has agreed to purchase, for 10 years, the higher summertime output.
If projections hold up, about 10,000 MWh worth of energy will be “transferred” to the City of Aspen through the PPA annually (although it is doubtful that any of the actual electrons flowing into the grid from the new hydropower plant will travel that far). This amount is not set in concrete – Berry emphasized that there will be annual fluctuations in the amount of power that is delivered to Aspen, depending on a number of factors including whether it is a wet or a dry year, the timing of the spring runoff, and the demands of downstream water rights holders.
Tri-County WCD has secured $15 million in financing for the project – including a $13 million loan from the Colorado Water Conservation Board, and a $2 million loan from Colorado Water Resources and Power Development Authority – and has sunk an additional $3 million of its own money into the project.
“We did an economic analysis based on $18 million, and we will probably build this thing for $17.5,” Berry said. Based on existing PPAs with Aspen and Tri-State, the project will be paid for by 2045, after which time the hydropower facility could net Tri-County WCD up to $1 million annually in revenues.
“If mother nature cooperates, we will have money to pay our bills,” Berry said. “If not, we will have to address that at the time. I hope that is not the case.”
HYDRO LEGISLATION UNDERWAY IN COLORADO
As the new hydropower plant at Ridgway Reservoir prepares to go online, legislation has been introduced at the state capitol to help streamline development of smaller hydropower projects throughout Colorado.
Last week, the Colorado House of Representatives overwhelmingly passed HB14-1030 by a vote of 62-3. The bipartisan legislation complements the recent streamlining of federal permitting requirements for small hydro through the Hydropower Regulatory Efficiency Act.
HB14-1030 was introduced in the House by Reps. Mitsch, Bush and Coram. Senator sponsorship includes Senators Schwartz and Roberts as well as Hodge.
In essence, the bill “makes it possible to simultaneously complete federal and state review at the same time,” said Kurt Johnson, the president of the Colorado Small Hydro Association. It also seeks to streamline the electrical inspection process for small hydro, using precedents set in the small wind industry decades ago.
The Senate Agriculture, Natural Resources and Energy Committee will hold a hearing on the pending legislation on Feb. 27.
email@example.com or Tweet @iamsamwright