Geothermal in Oregon Update

What do ancient Roman baths in Bath, England and Klamath Falls, Oregon, have in common? If you guessed togas, you are unfortunately incorrect. Both are locations of major developments in the early history of geothermal energy usage.

Geothermal energy is thermal energy created deep inside the Earth’s core. This energy radiates from the center of the Earth in the form of heat; starting from temperatures of over 9,000 degrees Fahrenheit. We can thank geothermal energy for the geographical formations that have shaped life on this planet for millennia. Why? Geothermal energy turns solid rock into magma, which bubbles out of the earth’s crust to form volcanoes and new landmass. It heats underground reservoirs of water, creating steaming hot springs that dot our planet. To learn more about geothermal, take a look at our two part series on Geothermal Power in Oregon Part I and Part II that give an introduction to geothermal power as well as a list of advantages and disadvantages of geothermal.

Ancient human civilizations recognized the benefits of harnessing this hidden source of energy for bathing and heating. China is the site of the world’s first hot spring bathing pool, built in the 3rd century BC. The Roman baths in England used geothermal energy to heat the bath water and warm the bathhouses’ floors during the 1st century AD.  In the late 1800s, Klamath Falls, Oregon, became the location of the world’s second district heating system (the first was built in Boise, Idaho, eight years earlier). This innovative, low-cost system extracts heat from the geothermal energy source from underground and distributes it among a network of buildings to provide warmth. In Iceland, over 50% of buildings are heated in this manner. As of 2009, over 28 gigawatts of direct geothermal heating capacity is installed worldwide for district heating and other applications, including space heating, spas, industrial processes, desalination and at agricultural sites.

The idea to use geothermal energy to produce electricity was first tested in the early 1900s. We’ve come a long way in the past 120 years: over 10,715 megawatts (MW) of geothermal power are now being generated annually in 24 countries. In fact, the United States is the world’s largest producer, putting out 3,086 MW each year. The potential for more geothermal power is staggering. A 2007 Massachusetts Institute of Technologyreport estimated that geothermal power plants across the world could be generation 100 GW of electricity - equivalent to 1,000 coal-fired or nuclear power plants - by 2050, and has the capability to produce a large percentage of the nation’s energy needs for centuries to come.

Geothermal power plants generate electricity by transforming geothermal energy into electricity. The common method used to do this takes advantage of a natural process called hydrothermal convection. Water beneath the earth’s crust is being heated by the geothermal energy and rises toward the surface. The plant drills shafts into the bedrock (typically no deeper than 1.5 miles) to capture that hot water and transform it into steam, which drives turbines that generate electricity. The original water is now cooler and is put back into the earth, to prolong the life of the geothermal hot spot.

A recent development technique is referred to as Enhanced Geothermal Systems (EGS). Useful in areas where there is ample hot dry bedrock but little water, EGS puts water into the dry environment to mimic the ideal conditions for a geothermal operation. This is done by drilling shafts into the hot layers of rock, injecting water into the shafts, and collecting the heated water as it comes back up to produce steam, move turbines, and generate power. Three EGS plants are operational in Europe and over a dozen more are in various stages of construction. Here in Oregon, Bend is the site of an EGS demonstration project being developed by Alta Rock Energy and Davenport Newberry with a Department of Energy grant.

The benefits of geothermal power revolve around its reliability, low environmental impact, and minimal cost in comparison to other energy sources, particularly fossil fuel sources. Geothermal energy is always present – thus a geothermal electricity plant can run 24 hours a day, 7 days a week, and can serve as a constant source of electricity for the grid. While drilling for and burning fossil fuels takes an enormous toll on our physical environment and increases our carbon emissions dramatically, geothermal energy is a cleaner source of power.

It’s not a 100% emissions free process because small quantities of greenhouse gases, in particular carbon dioxide, methane, and hydrogen sulfide, are drawn up along with the water during power generation. However, geothermal power plants are responsible for a miniscule amount compared to conventional fossil fuel plants; one study estimated the emission intensity per megawatt-hour of a geothermal power plant to be one-eighth of a typical coal power plant. Another concern related to the EGS process is the potential for land instability and small seismic events due to the drilling. Continual improvement of drilling and plant operation techniques promise to minimize this risk.

Klamath Falls, a city of 20,000 residents in southern Oregon, demonstrates how a city can utilize geothermal energy to save money, be “green”, and provide reliable services to its citizens. The City operates a geothermal district heating system to heat commercial and governmental buildings in the downtown. Additionally, the hot water being drawn from the earth is used to heat sidewalks and some bridges in the city, ensuring no snow or ice build-up in the winter months, so this highly innovative use of geothermal energy makes for a safer Klamath Falls too! In addition to heating the downtown core, over 600 geothermal wells are installed in private residences, schools, and a hospital to provide heat.

The future for geothermal energy looks promising. A 2011 research project at SMU documented the geothermal resources of the United States and found the potential for over 3 million MW of geothermal power production. Recognizing its small carbon footprint, the Obama administration has directed the Department of Energy to fund 123 demonstration projects in 38 states. They are developing and deploying technologies to support more efficient heat pumps and power plants and improve drilling, exploration, and underground mapping processes.

Oregon, with an abundance of geothermal resources, is working to promote the adoption of geothermal energy technologies. The Energy Trust of Oregon offers cash incentives and project development support to commercial, industrial, governmental, and agricultural organizations who are interested in constructing a geothermal electric system on their premises. (As with any Energy Trust of Oregon program, organizations must be a customer of PGE, Pacific Power, NW Natural, or Cascade Natural Gas.)

To learn more about geothermal energy, check out the Department of Energy’s Geothermal Technologies Program, the Oregon Department of Energy’s geothermal energies website, and Union of Concerned Scientists’ explanation of geothermal energy.

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