Energy policy — geothermal: Aspen to drill test bore to assess geothermal potential

A picture named geothermalenergy.jpg

From The Aspen Times (Andre Salvali):

Lauren McDonell, environmental initiatives program manager for the city of Aspen, explained the plan to four [Aspen’s Open Space and Trails Board] members before their vote and said that geothermal energy could be another way for the community to reduce its carbon footprint. “If we’re sitting on top of a clean, renewable, carbon-free source of energy, I think we have a responsibility to explore it,” she said. “It could help us decrease our dependence on fossil fuels, and help us address climate change in Aspen. So it’s kind of an exciting opportunity.”[…]

The city likely will start the test well in late September, drilling up to 1,000 feet below the surface of the parking lot. If answers can be obtained at a shallower depth, the city won’t need to drill any deeper, she said. The nearby Roaring Fork River won’t be affected, McDonell said. The parking lot is located within the Prockter Open Space, which is why permission from the city’s Open Space and Trails Board was needed. The test site is simply that, McDonell said, explaining that it’s unlikely to be used as a production area should the city move forward with a geothermal energy project. However, it could be used for future monitoring and tests…

The project is expected to take 30 to 45 days, McDonell said. Noise from the test site will be kept at or below 55 decibels, the limit stipulated in a city ordinance based on the time of day and area of town…

According to a city news release, the test site lies just west of old silver mine workings. The project won’t disturb any heavy metal deposits in the area. “We wanted to pick a site that is city-owned and as close to old mine workings as possible without being in them,” consultant John Kaufman said in a prepared statement. “We are looking to find out the temperature of the water, the water chemistry, like if it is hard water or alkaline and we hope not to find heavy metals in the water,” he said, adding that historical evidence suggests Aspen miners more than a century ago encountered hot water as they worked.

More coverage from Andrew Travers writing for the Aspen Daily News. From the article:

The board voted 4-0 for the drilling project, following a brief presentation by Lauren McDonnell of the city’s Canary Initiative, which is spearheading the initiative…

Board member Charlie Eckart asked how many truckloads of dirt and rocks would be produced from drilling. Just one every three to four days during drilling, McDonnell said. All the board members encouraged her to continue communicating proactively with neighbors about noise and other impacts from the test.

The city held a neighborhood meeting on Monday seeking feedback on the geothermal project from adjacent homeowners. Twelve neighbors attended that meeting. None attended Thursday’s meeting to oppose or support the project…

McDonnell will now begin searching for a drilling company to do the work. The contract for drilling will be subject to City Council approval later this summer. Drilling is scheduled to take place in mid- to late-September, McDonnell told the open space board. The parking lot will be closed up to 45 days during drilling and the subsequent testing of the hole…

Based on a 2008 geothermal feasibility study, the temperature of local underground water ranges in temperature from 90 to 140 degrees. To heat or cool buildings with geothermal energy, 100-degree water is required. To generate electricity, the city would need water of at least 220 degrees.

More coverage from Andrew Travers writing for the Aspen Daily News. From the article:

The potential of tapping local renewable energy sources like geothermal has drawn support from the city’s Canary Initiative, which aims to reduce local greenhouse gas emissions by 80 percent before 2050. Geothermal energy taps the consistent temperatures below ground to heat or cool interiors above ground. “We’re excited that if we find the geothermal potential we’re talking about, it could be enough for heating and cooling buildings in Aspen with a local clean energy source,” said Lauren McDonnell, director of the Canary program…

If the Prockter test site is successful, McDonnell said, the city would drill a second test well on another public site before actually tapping any geothermal energy…

The city’s hopes for geothermal resources are based largely on historical accounts from 19th century silver miners in Aspen. “The miners encountered very hot, uncomfortable conditions in the mines here,” Kaufman said. That anecdotal evidence led the city to conduct a feasibility study for local geothermal in 2008, which found the temperature of underground water in Aspen ranged from 90 to 140 degrees. Drilling for geothermal, however, will avoid the vast network of mining tunnels below Aspen, Kaufman said, because they are not structurally sound.

More geothermal coverage here and here.

Leave a Reply