In 2010, Colorado produced more than one and a half million megawatt hours of electricity using hydropower.
While this accounted for less than 4 percent of total electrical generation in the state, technological advances and streamlined regulations are improving the outlook for adding more of this energy source to Colorado’s power mix.
Colorado has more than 60 hydropower units collectively capable of producing 1,160 megawatts of power at any given time. One quarter of that installed capacity comes from three dams on the upper Gunnison River—the Crystal, Morrow Point and Blue Mesa dams of the Aspinall Unit, which collectively produce up to 288 megawatts. These dams were constructed in the early 1960s to store water for the upper Colorado River Basin; adding hydropower became an incidental purpose, says Bureau of Reclamation hydrologist Dan Crabtree. Today, that power—enough to supply as many as 100,000 homes—is sold to municipalities, public utilities and governmental agencies in Colorado and surrounding states through the Western Area Power Administration.
Large facilities like the Aspinall Unit are unlikely to be built today, however. “Ecological damage basically restricts development of large-scale hydropower, especially on mainstem rivers,” says Crabtree.
New projects are much smaller—and take advantage of existing infrastructure. Reclamation currently has several new hydropower projects underway in Colorado: The Dallas Creek Project on Ridgway Dam on the Uncompahgre River and the South Canal Hydroelectric Project downstream near Montrose will each generate close to 8 megawatts, together providing enough electricity to power more than 5,000 homes annually. Affordable construction loans and power purchase agreements with Aspen and Tri-State Generation and Transmission made the projects feasible.
Typical impediments to hydropower development include expensive start-up costs, although hydropower has a longer economic life and costs less to maintain and operate than other renewable energies, says Brad Florentin, senior engineer with AMEC, a consulting firm that works on energy projects worldwide.
Acquiring power purchase agreements can also be difficult, as well as securing necessary permits—but that recently became easier with the passage of two bills signed into law by President Obama in August 2013. The Hydropower Regulatory Efficiency Act, introduced by Colorado Rep. Diana DeGette, and the Bureau of Reclamation Small Conduit Hydropower Development and Rural Jobs Act, introduced by Colorado Rep. Scott Tipton, should shorten regulatory timeframes, as well as expedite small hydropower development at existing Reclamation-owned canals, pipelines, aqueducts and other waterways. Moving more quickly than many expected, the Federal Energy Regulatory Commission approved its first application, for a project in Idaho, under the new legislation in October 2013—a promising sign to small hydro advocates.
In 2011, Reclamation identified 37 additional sites where hydro facilities could be installed on existing dams in Colorado. Tapping those resources could generate another 242,000 megawatt hours of electricity per year, says Reclamation’s senior advisor for hydropower Kerry McCalman. In 2012, the agency identified an additional 28 sites on the state’s irrigation canals with the potential for generating 100,000 megawatt hours annually. Together, the retrofits could supply 40,000 homes.
Still, Colorado hydropower will never compare to a state like Washington, whose Grand Coulee Dam on the Columbia River alone produces more than 10 times the amount of hydropower of all that is generated here—Colorado streamflows simply can’t compete with such a massive river.
Reducing Hydro’s Impact
Hydropower accounts for nearly two-thirds of all renewable energy generation in the nation, according to the U.S. Department of Energy. Generally considered a “clean” energy source because there is no fuel combustion and little air pollution compared with generating energy using fossil fuels, hydropower facilities still have their drawbacks.
Large dams, for example, have significantly impacted rivers by altering their flow patterns, in some cases virtually wiping out native species. Under natural conditions, high springtime flows inundate floodplains, providing both nursery areas and quiet water habitat for adult fish prior to spawning, says Patty Gelatt of the U.S. Fish and Wildlife Service Western Colorado Field Office.
In 2010, Reclamation began implementing new operating strategies for its 288-megawatt Aspinall Unit to help endangered fish and critical habitat, increasing water releases in the spring to mimic the river’s natural seasonal flow, though such efforts have come at a cost to total power generation.
Fish, which need well-oxygenated water, can also be impacted by the oxygen-reducing effect turbines have on flowing water. Oxygen is restored naturally when water flows over rapids, or ripples. In some cases, engineering structures are installed in rivers to replicate that re-aeration effect. Other mitigation efforts include fish passages and ladders to help migrating fish navigate over dams and electronic fish barriers to prevent fish from swimming into areas where they risk being struck by turbines.
To be considered, and certified, “low-impact” by the Low Impact Hydropower Institute, projects must meet criteria for minimizing these types of impacts. Such certification, the institute notes, could be a selling point for marketing power from hydro projects.
Big Potential for Small Hydro
Although the days of building new, large-scale hydropower projects are likely limited, possibilities abound in Colorado to install power-producing turbines on existing infrastructure. Such “micro-hydro” technology captures the energy of water moving through the state’s irrigation and municipal systems, often in order to power on-site operations.
The Colorado Department of Agriculture has hired Applegate Group, a Colorado-based engineering and consulting firm, “to create a roadmap for the Department to successfully support the development of small agricultural hydropower,” says Applegate water resources engineer Lindsay George. One notable success is a project on the Wenschhof cattle ranch in Meeker, where Applegate assisted with securing funding, permitting, construction and commissioning of a 23-kilowatt hydropower system that provides for all of the ranch’s electrical needs—at a projected savings of $350,000 in utility costs over 30 years.
Applegate also worked with the Colorado Energy Office on the recently published Colorado Small Hydropower Handbook. The handbook is a resource for utilities, farmers and ranchers, and others interested in developing the resource, focusing on projects of 2 megawatts or less. Good prospective sites for adding small hydropower are characterized by existing infrastructure, such as dams and pipelines, consistent water flows, and at least 15 to 20 feet of “head,” or water level difference, says George.
Grand Junction is one municipality that has utilized the technology, developing micro-hydropower at its Kannah Creek Water Treatment Plant a few years ago. Utilities manager Terry Franklin helped design a 30-kilowatt system that generates enough electricity to run the facility, saving $8,000 a year in energy costs. Payback for the $50,000 project was just over six years.