It’s been three decades sice geophysicist William “Will” Gosnold began wondering about climate change and, on the flip side, began studying alternative sources of energy such as geothermal.
“The first research I did right out of grad school was geothermal,” said Gosnold, professor and chair of the UND Department of Geology and Geological Engineering.
“At the time I was doing that research, OPEC’s oil embargo had severely impacted fossil fuel prices, and I got a federal grant to measure energy gradients in the midcontinent area to see what might exist,” Gosnold said. “It turned out there were huge thermal resources there, but few applications. We saw some space heating and industrial uses, but no electric power.”
His early work led Gosnold to join a worldwide push to document whether there was anything going on with global climate. No question about it now: the Earth’s climate is changing, said Gosnold, who was awarded the Chester Fritz Distinguished Professorship, UND’s highest academic accolade, in 2006.
The United Nations Intergovernmental Panel on Climate Change (IPCC) 2007 report concluded, after more than 20 years of intensive research, that humans had caused most recent warming. That report earned the IPCC a Nobel Prize (shared with former U.S. Vice President Al Gore), and it was co-authored by UND mathematician and climate change expert Andrei Kirilenko.
“There’s absolutely no doubt about the reality that our climate is changing and that we are largely responsible for that change,” said Gosnold. “The big question is, what are we doing about it?”
North Dakota potential ‘huge’
For Gosnold and his colleagues at UND and elsewhere, part of the answer is a concerted push to find sustainable, non-polluting energy sources, including geothermal. His expertise is well-documented: as Custodian of the Global Heat Flow Data Base of the International Association of Seismology and Physics of the Earth’s Interior, he’s clearly considered by his peers to be a leading authority on, among other things, geothermal energy.
Will Gosnold, Chester Fritz Distinguished Professor of Geology and Geological Engineering, and department chair
He also is director of UND’s Petroleum Research, Education, and Entrepreneurship Center (PREEC). State funding of $3 million for that effort is matched by nearly $8 million in donated software and cash from private sector participants and alumni, Gosnold noted. The PREEC team includes Gosnold’s geology department colleagues Zheng-Wen Zeng and Richard LeFever. Mike Mann (chemical engineering) and Hossein Salefar (electrical engineering) are working with Gosnold and Zeng on the geothermal side of the equation.
“In addition to figuring out how to responsibly and economically recover more oil from North Dakota’s oil reserves, part of our mission is to develop enhanced geothermal systems using oil field waters to generate electrical power,” Gosnold said. “And the fact is, as we’ve noted before, North Dakota is potentially a huge and very reliable source of geothermal energy.”
What is geothermal?
Geothermal comes from the Greek roots geo, or earth, and therme, or heat. It is energy produced by the Earth itself. In North Dakota’s case, it means lots of hot (often boiling) water associated with the crude oil that’s buried deep in the Bakken Formation in the western part of the state.
“It’s the energy that heats hot springs, known since ancient times. Unfortunately you can’t send that kind of energy down a wire,” Gosnold said. “What we’re exploring here is how to efficiently use geothermal energy to generate electricity.”
Today, he said, geothermally generated electricity accounts for only 0.3 percent of global electricity demand, and the United States is the world’s largest user of electrical power from geothermal energy.
Right now, only four states have geothermal power plants: California, with 33 geothermal power plants that produce almost 90 percent of U.S. total geothermal electricity; Nevada, with 14; and Hawaii and Utah, each with one geothermal power plant. PREEC scientists and engineers are working to put North Dakota in those ranks soon, Gosnold said.
“There simply wasn’t a cost-effective way of using the Earth’s lower-temperature geothermal resources to generate electricity,” Gosnold said. “But now, improved technologies point to ways in which we can effectively tap that sustainable, and very clean, energy source.”
One key element of geothermal is that it doesn’t use much land: existing geothermal plants use from 1 to 8 acres per megawatt versus 5 to 10 acres per megawatt for nuclear operations and 19 acres per megawatt for coal power plants, Gosnold explained.
According to the U.S. Department of Energy (DOE), the best news is that there’s enough heat in the Earth to theoretically meet global energy demand for 10 billion years.
Focus on binary-cycle
There are three basic types of geothermal power plants, Gosnold explained. Dry steam plants use steam piped directly from a geothermal reservoir to turn the generator turbines. Flash steam plants take high-pressure hot water from 3 to 4 kilometers below the surface and convert it to steam to drive the generator turbines. Most modern geothermal power plants are flash plants. Binary power plants — the kind PREEC is closely researching — transfer the heat from geothermal hot water to another liquid.
This technology allows the use of much lower temperature geothermal fields that were previously unrecoverable. In 2006, a binary cycle plant in Chena Hot Springs, Alaska, came online, producing electricity from a record low geothermal fluid temperature of 57 degrees Celsius.
“Binary power plants work sort of like reverse air conditioners,” Gosnold said. “The big difference between binary cycle geothermal power generation plants and others is that the hot water or steam from the Earth source doesn’t contact the generator unit.
“Meanwhile, because they’re so abundant, moderate-temperature sites such as North Dakota oil wells running binary-cycle power plants will be the most common geothermal electricity generators.”
According to the DOE, geothermal power plants do not burn fuel to generate electricity, so their emission levels are very low. They release less than 1 percent of the carbon dioxide emissions of a fossil fuel plant.
The Bakken Formation (USGS graphic)
The DOE recognizes the strategic value of geothermal electricity, and supports its development in several ways through its Geothermal Technology Development Program.
First, it works with Congress to ensure support for geothermal energy and renewables in general. Second, it sponsors millions of dollars in research and development at national laboratories and universities. Investigators are working on issues in exploration, geochemistry, drilling, resource usage, and equipment operation. Third, through its “GeoPowering the West initiative,” the DOE works with state and local officials and other stakeholders to identify and overcome regulatory and institutional barriers to geothermal power development.
The Geothermal Technologies Program expects to receive additional funds through the American Recovery and Reinvestment Act of 2009.
“I’m really excited about all of this, especially since we know that North Dakota has enormous resources in this area that we can actually use to do something very positive for the environment,” Gosnold said.