Why is there no snow on these stairs?
I’ll give you a hint: It has nothing to do with shovels or salt.
The answer can’t be found in the picture, actually, because the secret of the melted snow is sealed beneath the concrete.
These particular stairs ascend to the Klamath County administration building in Klamath Falls, Oregon, and they’re kept warm by geothermal energy.
In honor of Earth Science Week 2010, this post is about this year’s theme: Exploring Energy. Specifically, I want to explore one Oregon town’s ambitious goal of harvesting renewable geothermal energy.
In 1981 the city of Klamath Falls, Oregon enlisted the help of the local campus of the Oregon Institute of Technology to tap into the deep geological heat sources of the region. They drilled a well more than 1300 feet deep and tapped an aquifer there with water at temperatures exceeding 190° F. Using that heat source, city developers installed a geothermal heating system designed to alleviate the burden of high energy costs for buildings in the city center. The project didn’t get off to a particularly smooth start; a study of the aquifer was required to satisfy the concerns of the public, and the design teams encountered problems with the water distribution piping early in the operation. But these challenges were overcome and the system has been providing reliable service since 1991.
Now, the elaborate plumbing system snakes through downtown Klamath Falls, heating 24 buildings (including a local brewery), 150,000 sq. ft. of greenhouses, the city’s wastewater treatment plant, and over 100,000 sq. ft. of sidewalk snowmelt systems.
Fancy as these new geothermal technologies are, the city planners in Klamath Falls are far from the vanguards of the geothermal revolution. The value of the natural heat sources in the Cascades was well known to the Native Americans who lived in the region long before European settlement. The natives made use of the abundant hot springs and mud pots. White settlers, once they arrived, were quick to catch on as well. In the 1890’s, shepherds were digging holes near artesian wells to tap the hot water, and the practice of drilling deeper pump wells became commonplace by the late 1920s.
Even in modern times, it was the Oregon Institute of Technology that began to test the potential of this local energy source when they completed their first geothermal heating system in 1964. Now that system heats the entire 650,000 square feet of campus and saves the school upwards of $1 million per year over comparable natural gas prices.
OIT broke new ground in Klamath Falls again when, in 2007 it drilled an additional well to access an even deeper and hotter source of water. This new well reaches more than 5,000 feet below the surface and draws up water at temperatures around 300° F. Temperatures this high are sufficient for generating electricity, which is exactly what the school administration, scientists, and engineers had in mind. The success of this latest project has earned the OIT campus the honor of being entirely energy independent.
Reliable, renewable energy is sure to be one of the crises of the 21st century. With pressure building to remove ourselves from dependence on fossil fuels, politicians, optimists, and opportunists alike are willing to point to any emergent technology as a potential panacea. For all of it’s utility and green credentials, geothermal power is not a cure-all, and some serious questions remain about the viability of these projects.
Tapping geothermal energy usually means tapping an aquifer, and as with any well, engineers face the potential for drawdown (is the water being pumped out faster than it is naturally recharged?) or subsidence (as we relieve pressure deep under the Earth, do we increase the risk of seismic hazards or the creation of sinkholes?).
Even when these issues are minimal or can be mitigated, we still have limitations based on the available geothermal potential. Fortunately for those of us in the west, geothermal resources are abundant and wide spread. The map below shows potential and known geothermal resources for Oregon and the nation as a whole.
If you want to learn more about the Klamath Falls projects and the work being done at the Oregon Institute of Technology, please check out their (rather outdated) website at: http://geoheat.oit.edu.
Brown, Brian P.E. Klamath Falls Geothermal District Heating System at 25 Years. Geo-Heat Center Bulletin, June 2007.
Geothermal Potential Across the U.S. The Arizona Geological Survey, 2009.
Oregon Geothermal Resources. U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Geothermal technologies Program, Nov. 2003.
Boyd, Tonya L. New Snow Melt Projects in Klamath Falls, OR. Geo-Heat Center Bulletin, Sept. 2003.