Energy & Environment

Geothermal: The Other Alternative Energy Source

Geothermal energy isn’t perfect. But in Colorado, its list of drawbacks is very short. The state's Capitol building is getting a new heating and cooling system -- powered by geothermal energy.
by | January 2011

To many people, the word “geothermal” evokes hot springs and geysers. To a few more, it’s an alternative energy that falls behind more familiar sources such as solar, wind and tidal. But to those versed in renewable energies, geothermal energy -- the heat simmering within the earth’s bedrock -- is hot.

Long overlooked because it can be hard to find and expensive to produce, geothermal energy got a boost last year in the form of $340 million in stimulus funds to help developers and researchers test new geothermal technologies. That, along with state requirements that utilities generate more power from renewable resources, is giving the already $1.5 billion geothermal industry new life.

Attractive because it is always available -- unlike wind and solar -- geothermal power is produced by drilling deep into the ground and extracting steam or hot water through tiny fractures in the rock. A 2007 U.S. Department of Energy (DOE) report estimated that advanced geothermal power could produce as much as 60,000 times the nation’s annual energy usage. But because large earthquakes tend to originate at great depths, seismologists say that breaking rock so far down carries serious risks. In addition to the expense of drilling, geothermal development also means additional competition for water, more holes in the ground and more roads to service those extraction sites.

In Colorado, however, geothermal is looking more and more like an ideal solution. It’s plentiful there, and geothermal extraction sites can be built in dense urban areas. In October, Colorado’s Capitol began a $6 million renovation that includes a new geothermal heating and cooling system. The “open-loop” system involves drilling two wells 900 feet into the Arapahoe Aquifer, near the Capitol. Water that is a consistent 55-degree temperature will be pumped from the aquifer through one well to heat and cool the building, before being reinjected into the aquifer through the second well.

The Capitol, which opened in 1894, will be among the first in the nation to have its own geothermal heating and cooling system, according to Gov. Bill Ritter’s office. The changes are expected to save $95,000 on utility bills in the first year, and should reach $165,000 by 2029, according to Lance Shepherd, manager of design and construction programs for the Division of Central Services. A similar geothermal system was installed at the governor’s residence in 2009, which has reduced the building’s natural gas use by 70 percent and electricity consumption by 15 percent.

The state Capitol is part of a geothermal trend in Colorado, according to the National Renewable Energy Laboratory (NREL). The state has already installed geothermal systems in schools and municipal buildings. Ikea, the international home furnishings retailer, is adding a geothermal component to the heating and cooling system in its new store in Centennial, a Denver suburb. Ikea has agreed to let NREL monitor the system’s performance as part of an effort to develop a database containing cost and performance data for multiple geothermal projects.

To encourage these geothermal projects and others, Ritter, the DOE and the Colorado Housing and Finance Authority in December announced two new programs that will finance energy-efficiency improvements in commercial buildings and renewable energy businesses in the state. The Green Colorado Credit Reserve is expected to serve more than 160 businesses and generate $7 million in new lending, while the Governor’s Energy Office Revolving Loan Program has set aside $13 million to help with large-scale retrofits or companies whose products directly impact the renewable energy sector in Colorado.

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