Voices

Power comes from within … the Earth’s crust

September 2, 2010


I’m a believer in climate change, but I can see why skeptics are hesitant to embrace the science behind it and rush out to find clean energy sources.  But climate change or no, one thing about the way we produce energy in the U.S. is certain: all of our major energy resources are non-renewable. Given the finite amounts of resources at our disposal—the big three being coal, natural gas, and oil—and the population growth that the U.S. is predicted to experience, it seems inevitable that increased demand for energy will threaten our security, development, and the economy, even if you don’t believe it will threaten our environment. “Where will we get our energy from in the future?” is a question that should be on everyone’s mind.

Solar panels, wind turbines, and nuclear reactors: These are the typical alternative energy sources present in the average American’s lexicon. But a vast array of lesser-known technologies has the potential to provide significant amounts of emission-free, completely sustainable energy, too.  This summer I traveled around the world researching one such technology, enhanced geothermal systems.

While it sounds fancy, the concept is very simple.  If you drill down deep enough into the Earth’s crust, the temperature becomes incredibly hot.  In places where reservoirs of fluid exist and are heated up by the surrounding rocks, traditional geothermal systems can pump this fluid up to the earth’s surface and use the hot water and steam both for direct-use heating and turning turbines for electricity generation.  EGS uses the same concept, except without the pre-existing fluids.  In EGS, a well is drilled and water is then used to expand fractures in the earth’s crust.  The water flows through these cracks and is heated up by the surrounding bedrock.  Then the hot water and steam is intercepted by another well, and used directly or used to generate electricity.

Geothermal energy has huge potential worldwide.  There are many numbers being thrown around, but an MIT-led study in 2007 estimates the potential U.S. output of geothermal energy is approximately 130,000 times greater than annual primary energy consumption. And unlike solar and wind, geothermal provides power 24 hours a day.

Okay, geothermal is great. Cool.  Why haven’t all of our energy problems been solved already?  Industry experts, technical specialists, and policy makers say that, by nature, EGS is a high-risk, high-investment technology.  The deep drilling (up to 10-km depths) involved increasing costs exponentially compared to traditional geothermal, which goes to maximum depths of two and a half miles. Limitations on modeling technology also make it difficult to determine the productivity of potential reservoirs, increasing the chances that geothermal projects will fail.

One of the most publicized concerns is the induced seismic activity that can result from hydro-fracturing, most notably in Basel, Switzerland, where it evoked enough negative press to shut down the project. Geothermal needs a strong marketing and public relations sector to ensure that energy generated has a market, that communities will allow for development and that tangible policy changes can occur.

The technology needed for geothermal is available, and becoming cheaper every year.  The cost of drilling, however, has risen dramatically—as demand for fossil fuels increases, the demand for drill rigs increases—significantly affecting project costs.  Drill rigs have become so expensive that companies in Australia, which has the most developed EGS industry next to the U.S., have stalled projects because they are unable to raise enough capital to qualify for the government funding available to EGS projects.

Still, hope remains for geothermal enthusiasts.  In places like Iceland and the Philippines, geothermal energy has been proven to work, and work well.  Geothermal energy in Iceland is so cheap that the government subsidizes families forced to heat their homes with oil due to lack of access to a geothermal resource, because oil actually costs more.  In the Philippines, companies like the Energy Development Corporation have used geothermal energy as a means to bring development into rural communities, sponsoring education, livelihood, and health programs, and providing employment for local laborers.

Moving forward, both in developed and emerging countries, policy will play a key role in the success or failure of geothermal energy. If investors can be assured of a switch to a clean energy economy, and prices become more consistent, the industry could flourish.  However, with all of the uncertainty surrounding the true cost of energy, it is difficult to attract enough capital to make a project viable.

As with most alternative energies, government involvement and funding is crucial during its infancy.  After learning about the potential benefits and costs of developing geothermal technology, I have become convinced that it will play a major role in our transition to a green society.  Of course, it is not the end-all cure to our energy problems, but I believe that it is a necessary component of our future energy supply.



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