MIT-led study finds geothermal energy potential untapped

Heat mining technology can be improved and deployed broadly to generate clean electricity, says an Energy Department-sponsored report.

A study led by the Massachusetts Institute of Technology has concluded that geothermal energy is a largely untapped resource for electricity in the United States.

The study (PDF), issued Monday, was sponsored by the Department of Energy and included the participation of 18 experts in geology, drilling and energy.

Jefferson Tester
Credit: Donna Coveney
MIT professor Jefferson Tester led
an 18-member panel of experts
studying geothermal energy.

With geothermal energy, or "heat mining," electricity is generated from hot rocks thousands of feet beneath the Earth's surface. Water is flowed into drilled wells, creating a heat exchanger that can produce hot water or steam to run electrical generators on the surface, according to MIT.

The United States already has geothermal systems operating in the West, but MIT concludes that the technology can be used broadly and be economical.

What's needed are improvements in deep drilling and technologies to manage the flow of water within wells, Jefferson Tester, professor of chemical engineering at MIT, said in a statement. Also required are demonstrations of large-scale operations and the ability to transfer technologies to different regions of the country, said Tester, who was head of the panel.

Further pursuing large-scale commercial geothermal power is important because the demand and price of fossil fuels--which generate the majority of electricity in the United States--continue to rise, MIT said.

Geothermal energy also has the advantage of being a domestic energy source and is cleaner than fossil fuels, according to MIT. Unlike wind and solar power, geothermal plants can operate at all times.

Risks associated with large-scale heat mining include meeting water requirements, according to the study. The potential for seismic risks is also an issue.

"Geothermal energy could play an important role in our national energy picture as a noncarbon-based energy source. It's a very large resource and has the potential to be a significant contributor to the energy needs of this country," panel member M. Nafi Toksöz, professor of geophysics at MIT, said in a statement.