From the Valley Courier (Ruth Heide):
In conjunction with Colorado State University and Colorado Department of Agriculture, Applegate Group, Inc., is currently studying the potential for low head hydro within existing irrigation systems in the state, including the San Luis Valley. A grant from the Advancing Colorado’s Renewable Energy (ACRE) Program is funding the study. Applegate will issue a report this fall regarding available technology for micro hydro, with 20-30 turbines identified as appropriate for a typical structure in irrigation ditches. The company is also sending a survey to irrigation companies and ditch owners to gather further information and will choose two sites in the state to perform a more complete analysis…
[Lindsay George, Ph.D., PE, an engineer with Applegate] said low-head hydro could provide a revenue stream for ditch companies, and utility companies have indicated an interest in potential power derived from such sources. “A lot of the co-op/utility companies are very receptive,” she said. “There’s a lot more interest in this than solar because this runs at night. A lot of the companies are interested.”
She said surveys are being sent to owners of irrigation companies and ditches with more than 100 cubic feet per second (cfs) decreed capacity because “that’s where the most power can be generated on ditches.” Applegate is interested in learning how much drop the ditches have on their systems and flow rates so the company can determine how much power could be produced. Low head power is between 5 and 30 feet, George explained. Turbines could be placed on chutes on existing diversion dams, she explained. She said people think of enormous turbines in connection with hydro electricity, but she has researched a variety of smaller, diverse turbines that could be utilized on irrigation ditches to produce low head hydro power. A small propeller type turbine, for example, would require as low as 125 cfs and 6-50 feet of head. Another small turbine, producing 1-180 kilowatts, would require 175 cfs and 5-20 feet of head…
Another emerging technology is the vortex power plant that is only operating now in Switzerland and Indonesia but is under consideration in Basalt. The turbine is located inside the vortex. One of the systems in Switzerland uses 4.5 feet of head and 30 cfs to produce 7.5 kilowatts. George said this type of system is 65 percent efficient.