Two proposed pumped water storage projects that could expand Colorado’s ability to store renewable energy – one in Fremont County and another between Hayden and Craig in the Yampa River Valley – are moving forward.
Colorado will need green energy storage of some type if it is to attain its mid-century goals of 100% renewable energy. Solar and wind power are highly variable and cannot be turned off and on, like coal and natural gas plants are.
So the search is on for ways to build large-scale storage projects to hold the energy wind and solar generate. Lithium-ion batteries are part of the answer and are being rapidly added to supplement wind and solar. But they typically have a short life span, while pumped water storage hydropower projects can operate for decades.
Pumped water storage has been refined in recent decades but the basic principles remain unchanged. Water is released from a higher reservoir to generate power when electricity is most in demand and expensive. When electricity is plentiful and less expensive, the water is pumped back up to the higher reservoir and stored until it is needed again.
This technology even today is responsible for 93% of energy storage in the United States, according to the U.S. Department of Energy. That includes Cabin Creek, Xcel Energy’s 324-megawatt pumped storage unit near Georgetown. It was installed in 1967.
“These pumped-storage projects are anathema to the modern way of thinking,” says Peter Gish, a principal in Ortus Climate Mitigation, the developer of the Fremont County pumped water storage project.
“But once built and operating, the maintenance costs are very, very low, and the system will last, if properly maintained, a century or longer. The capital investment up front is quite high, but when you run the financial models over 30, 50 or 60 years, this technology is, hands down, the cheapest technology on the market for [energy] storage.”
Ortus Climate Mitigation wants to build a 500-megawatt pumped water storage facility on the South Slope of Pikes Peak above the town of Penrose in Fremont County. This facility – essentially a giant battery for energy storage – would require two reservoirs.
Gish hopes to have a permit from the Federal Energy Regulatory Commission in 2026. Construction would take up to five years after the permit is approved.
In the Yampa Valley, another developer continues to plug away at a potential application for a site somewhere between Hayden and Craig. Still another idea is said to be in formulation in southwestern Colorado, but no details could be gleaned about that project.
Phantom Canyon, as Ortus calls its project in Fremont County, would require 17,000 acre-feet of water for the initial fill of the two reservoirs to be augmented by about 1,500 acre-feet annually due to losses from evaporation.
The company says it has accumulated water rights.
Gish, a co-founder of Ortus, says his company is “keenly aware” of water scarcity issues in Colorado and looks into ways to reduce the evaporative loss and hence shave water needs. One option is to place solar panels over the reservoirs, producing energy while shading the water. On a vastly smaller scale, that has been done at the Walden municipal water treatment plant in north-central Colorado.
Unlike an unsuccessful attempt by Xcel in 2021 to build a pumped water storage project in Unaweep Canyon on federal land in Western Colorado, the Ortus project near Pikes Peak would involve only private land. The company has exclusive purchase options for 4,900 acres. It also has secured 12 easements for pipeline access from the lower reservoir to the Arkansas River.
Proximity to water sources matters, and so does the location relative to transmission. Penrose is about 30 miles from both Colorado Springs and Pueblo and major transmission lines.
The company last year laid out the preliminary plans with Fremont County planners and hosted a meeting in Canon City to which environmental groups and others were invited. By then, FERC had issued a preliminary permit which is the start of the permitting process. Gish, who has worked in renewable energy for 25 years, says no potential red flags were noted.
“I have found that the local stakeholders are the first people you need to talk to about a project like this,” Gish says, “If you are able to get local support, the rest of the pieces will tend to fall into place. If not, the rest of the process is a much more difficult proposition.”
In Western Colorado, Xcel faced local opposition but also the more daunting process of permitting for a project on federal land. In the Craig-Hayden area, Matthew Shapiro, a principal in green energy company Gridflex Energy, had been examining sites that are on private land. Work continues on geological assessments and other elements, but he says that a “lot of other pieces need to come together before there is real progress.”
In addition to having water, that portion of the Yampa Valley also has the advantage of transmission lines erected to dispatch power from the five coal-burning units that are now scheduled to close between 2025 and 2030.
Shapiro hopes to also use Colorado-sourced water to generate electricity in a pumped-storage project on the North Platte River in Wyoming. Gridflex Energy filed for a license application with FERC last week for the project on Seminoe Reservoir.
“Very few projects have made it that far since the turn of the millennium. It’s a pretty big deal,” Shapiro said.
Long-time Colorado journalist Allen Best produces an e-journal called Big Pivots and is a frequent contributor to Fresh Water News.
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