CO State Capitol Is First To Boast Geothermal Heating & Cooling

It’s been a good year so far for renewable energy in Colorado. First, the state legislature passed a bill that doubles the amount of renewable energy that the state’s rural cooperative electric associations will be required to source by 2020. Second, it was recently announced that Colorado will be the first state capitol in the country to power all heating and cooling with geothermal energy.

The open-loop geothermal system taps into the Arapahoe Aquifer, which sits more than 850 feet underground and is a consistent 65 degrees. This system, recently brought online, is expected to save the 119 year-old building $100,000 in heating and cooling costs in the first year alone.

Colorado State Capitol

Image via Steven Kevil

To install the system, Chevron Energy Solutions drilled an 865-foot well under the state capitol, and ran a pipe into the Arapahoe aquifers below. Unlike a closed-loop system, an open-loop geothermal system is connected directly to a ground water source such as a well or pond and directly pumps the water into a building to the pump unit where it is used for heating and cooling. Open loop systems require access to a substantial water source, but are more cost effective.

In addition to the upgraded functionality of air conditioning to the building, the project will replace existing pumps and other equipment that date back to the 1940s and are well beyond their estimated useful life, avoiding approximately $904,000 in replacement costs, according to a press release [pdf].

The US Department of Energy is providing a $4.1 million grant toward the overall $5.5 million project. The state is financing just under $1.5 million to complete the project, reports Energy Manager Today.

“Everything is functioning at this point,” said Lance Shepherd, the manager of the State Capitol Geothermal Project, told the Denver Post. “We are still doing our commissioning and working the bugs out. It will be another month of going through that process.”

After its first year, it’s expected that financial savings will increase by 3 percent.

Beth Buczynski is a freelancer writer and editor currently living in the Rocky Mountain West. Her articles appear on Care2, Ecosalon and Inhabitat, just to name a few. So far, Beth has lived in or near three major U.S. mountain ranges, and is passionate about protecting the important ecosystems they represent. Follow Beth on Twitter as @ecosphericblog

1 Comment

  • Reply July 24, 2013


    We did a somewhat smaller open loop geothermal HVAC system for our house, so I have to ask: Are they pumping the water back into the ground? Why is Chevron confident that only going 15′ into the Arapohoe Aquifier is enough given the climate disruption connected risks of extended drought in the US Southwest? Does the system augment their hot water supply when the AC side is running? Why is the aquifier so warm? My general impression is that deep groundwater comes in at more like 55 degrees.

    Otherwise: Awesome savings!

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