Idaho State University researchers, colleagues explore tapping Southeast Idaho’s geothermal energy sources

It may not be hotter than Hades down there, but the geothermal energy trapped below the ground in Southeast Idaho is hot – the area's sub-surface heat flow is among the hottest known beneath the surface of the planet – and Idaho State University researchers and colleagues are trying to figure out how to tap into it.

"There is no other Snake River Plain/Yellowstone geothermal system on the planet," said Mike McCurry, ISU geosciences professor. "The magnitude of the system is enormous. It is a true world-class system of high heat flow and we’re just beginning to learn about how to get to it."

Geothermal is an attractive alternative energy source because it is clean and, in the future, could be economical to exploit.

McCurry and John Welhan, an Idaho Geological Survey/University of Idaho research scientist based in Pocatello, are mentoring a team of Idaho State University undergraduate and graduate students who are drilling wells this summer to test for geothermal energy sources. The students are examining new wells near Soda Springs in the Southeast Idaho highlands. They will also be looking at wells logs and data from other wells that were previously drilled near Newdale east of Rexburg on the edge of the Snake River Plain.

The group of ISU students is participating in a National Geothermal Student Competition sponsored by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy and the Center for Advanced Energy Studies in Idaho Falls. Nine other teams of students from around the United States are participating in the competition. The students will create professional-quality research reports using exploration technologies to further geothermal power development of the Snake River Plain in Idaho and present the results.

"Our students are going to develop a robust, creative and testable model for understanding (geothermal) heat sources in our area," McCurry said.

One of the challenges of tapping Southeast Idaho geothermal energy is the depth of its sources underground. The heat largely comes from past volcanic activity, which is dissipates for millions of years underground. A lot of that past activity in Southeast Idaho is underneath the enormous Snake River aquifer and deep underground. However, there are some low-angled diagonal faults, which are cracks in the earths crust, in the area. Near the top of the faults, closer to the surface of the earth, geothermal energy sources may be easier to tap.

The four ISU students – geosciences graduate students Michael Ginsbach, Rebecca Ohly, Adam Koster and undergraduate Holly Young – will be helping drill 1,000-foot deep wells and recording temperatures, rock properties, and the chemistry of the subsurface materials at different depths. This information will be used to make models of what is going on deeper underground.

"We will be looking for anything that suggests the presence of geothermal systems and how intense they are," Ohly said.

She is one of the students helping drill the well near Soda Springs near the China Hat lava flow. This is one of the youngest rhyolite lava flows in North America that has the potential for strong geothermal energy. One aspect the students here will be testing is to see if subsurface temperatures increase nearer to the surface as they head east, along a fault.

The results from the China Hat flow will be compared to the results from the Newdale site located on the much larger, older volcanic flows under the Snake River Plain.

The students at both sites are testing for geothermal energy in areas that have existing power transmission infrastructure so if those energy sources are found and developed they can be connected to existing infrastructure.

"I think we have a unique project that can potentially be applied to similar areas," said Ginsbach, who is working the drill site near Newdale. "This project potentially has a large scope. We're focusing on the Snake River Plain and near China Hat were Drs. Welhan and McCurry have done a lot of work. They're excellent mentors to be working on this with."

All the study's participants commented on the collaborative nature of the project, which includes input from Idaho's universities, the Department of Energy, private companies and the Center for Advanced Energy Studies.

"I really like the idea that we can contribute in a real way to developing alternate energy systems," Ohly said. "It is very cool and very relevant right now."

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