On the Newberry Volcano in central Oregon, a power plant may hold the potential for providing an enormous clean energy resource to the United States.
AltaRock Energy is working on turning geothermal energy into a widespread reality through an emerging trend in extraction called “enhanced geothermal systems,” or EGS. The main resource needed for extraction is hot rock housed at a reasonable depth, of which there is an abundance in the U.S.
In 2005, an MIT interdisciplinary panel pointed to the promise of geothermal energy initiatives in reducing global dependency on finite fossil fuels and fickle sources of renewable energy such as wind and solar power. Soon after, in 2007, AltaRock Energy was formed. The MIT group specifically investigated what would be necessary to produce 100,000 megawatts of geothermal energy in North America by 2050, which represents about 10 percent of overall U.S. generating capacity.
Geothermal energy is potentially entirely renewable, and requires less land than solar or wind power, while also being able to produced energy around the clock. Infrastructure for accessing this power leaves little carbon emissions, making it a highly hopeful technology amongst clean energy experts. It works via hot water and high temperatures in the earth’s crust, essentially harvesting the power of geysers for usable energy.
Geothermal energy has existed in many forms throughout human civilization, often used for heating smaller spaces like individual homes or buildings that sit on hot springs. This has typically meant that harvesting geothermal power has been restricted to locations where geothermal activity was naturally plentiful and found in shallow drilling depths. In recent attempts to access this energy, larger-scale production wells drill deeper for more intense heat, 5,000-10,000 feet below the surface.
These initiatives are expensive, with greater depth usually translating into greater prices due to danger to equipment, time and potential exploration costs. These conventional geothermal wells cost at least $5 million to develop, and about half fail. EGS promises to bypass these restrictions and develop resources anywhere, regardless of natural potential.
Although the comparison may be unfavorable, the science behind EGS has some uncomfortable similarities to commercial fracking. Millions of gallons of water and chemicals are injected into mostly vertical wells at relatively high pressure where there was no water before. When cold water meets the hot rock, it breaks it apart. The new technique can reduce the failure rate of conventional geothermal plants and extend the size and life of existing geothermal fields. In time, the idea is that EGS will allow geothermal fields to be established wherever there is suitable hot rock, of which there is practically no limit.
Like fracking, EGS can trigger earthquakes. Most are small, and proponents of EGS argue that they can barely be felt if correctly controlled. But an early project on a seismic fault in Basel, Switzerland in 2006 was scrapped after a 3.4 quake. Concerns have also been raised regarding toxic chemicals that could be released by fractured rocks, resulting in contaminated soil.
The venture is also not cheap, and debates on the cost-effectiveness of geothermal have ranged widely. The 2005 MIT panel indicated that in order to commercially deploy EGS energy by 2050, public/private investments would total between $800 million and $1 billion over a 15-year period. Although this is a hefty price tag, the panel also noted that this is “less than the cost of a single new-generation, clean-coal power plant.” The AltaRock Newberry Volcano site alone has been underwritten by a $40 million commitment from private investors, including Kleiner Perkins, Caufield & Byers and Google, in addition to a $21.5 million grant from the Department of Energy. The venture is also supported by a number of universities and scientists.
However, Douglas Hollett of the Department of Energy calculates that EGS adds capacity to existing geothermal fields at a cost of 2-5 cents per kilowatt-hour. For low-cost natural gas, the equivalent is 6-7 cents.
America has the world’s highest installed capacity of geothermal generating plants – 3.4 gigawatts’ worth at last count – yet these plants generate only 0.4 percent of American power. The United States currently stands as the most promising nation for promoting geothermal energy due to its numerous geysers and volcanoes. These are ideal resources for drilling and harnessing geothermal energy on a large scale and come without the potential hazards of EGS.
Until then, it seems “enhanced” methods can only guarantee geothermal energy’s universal potential at the threat of its eco-friendliness, the extent of which remains to be seen.