From The Denver Post (Mark Jaffe):
On Feb. 11, the Bureau of Land Management is scheduled to offer the first lease for geothermal development in Colorado — 800 acres in the Chalk Creek Valley. Why the valley? Because an unidentified party nominated the land for lease sale. It is bureau policy not to reveal the nominator until after the sale. And following a congressional mandate, the bureau is trying to expedite geothermal leases in the West. “Congress voted for us to identify the low-hanging fruit, get out of the way and let the market decide,” said Kermit Witherbee, manager of the bureau’s national geothermal program…
“The whole process seems to have been fast-tracked without a lot of details being worked out,” said [Syd Schieren who uses the geothermal water to heat his organic-vegetable greenhouse and], who lives and has hot spring vacation rentals in the valley…
The Chalk Creek Valley sits above the Rio Grande rift, which runs as deep as 10,000 feet and enables enough heat to reach within 3,000 feet of the surface to heat groundwater to about 150 degrees Fahrenheit, according to the Colorado Geological Survey. A geothermal electricity plant can tap into that hot water and bring it to the surface, where it is used to heat a fluid, such as isobutane, which boils at a lower temperature than water. The isobutane steam is used to turn an electric turbine, and is then condensed and collected for reuse. The water is reinjected into the deep rock reservoir to be reheated. A geothermal plant can run 24 hours a day, seven days a week. That makes it about five times as valuable as wind or solar, utility industry officials say. “It is baseload, and that is huge. It emits no pollutants or greenhouse gases,” said Jeff Lyng, renewable energy manager at the Governor’s Energy Office.
Based on the limited drilling and geochemistry data for Colorado, the current data show there are about five likely sites for geothermal plants, said Matt Sares, deputy director of the state Geological Survey:
• Strawberry Hot Springs, north of Steamboat Springs.
• The San Juan Mountains near Ouray and Rico.
• Pagosa Springs in Archuleta County.
• Waunita Springs, Gunnison County.
• Mount Princeton Hot Springs in Chaffee County.…at least two 2,500-foot test wells are needed to determine whether the heat and water flow are sufficient for a commercial project and show that the water table and other wells won’t be damaged, [Fred Henderson, a geologist and Nathrop resident, created Mount Princeton Geothermal LLC] said. That work could cost $2 million to $3 million, Henderson estimates.