In April 2024 Bill Nye ’77 returned to campus to celebrate the 150th anniversary of his Cornell major—mechanical engineering. With his signature enthusiasm, he spoke to an audience of all ages about how science helps solve thorny challenges, like global warming. He pointed to the Cornell University Borehole Observatory (CUBO) as an example of a game-changing solution.
“My CUBO, my borehole observatory: This is the future,” he said. “If we can harness the geothermal energy under North America, under everywhere, we can change the world.”
Earth Source Heat (ESH) has been a lynchpin of Cornell’s Climate Action Plan (CAP) since 2009, when it was included as an extremely efficient way to reduce emissions associated with heating campus.
According to Sarah Carson, director of the Campus Sustainability Office, heat accounts for 30 percent of campus greenhouse gas emissions.
“Heat remains our biggest hurdle to becoming carbon neutral by 2035,” Sarah observes. “Advancing ESH will enable Cornell to move beyond fossil fuels, and it could also rapidly reduce emissions in our region on a larger scale.”
From brainstorm to buildout
For the past 15 years, a dedicated team of staff in Cornell’s Energy and Sustainability department has been making steady progress to transform Earth Source Heat (ESH) from a novel idea into a working system to heat Cornell’s campus.
As good scientists do, they have questioned their assumptions, run the numbers to see if other options might work better, and—with due diligence—taken the vital first step in the buildout of the system: CUBO. The first phase of CUBO was completed in 2022, and the initial results are positive.
The temperature at the bottom of the observatory well is perfect: 180 degrees F°—hot enough to heat water that can be circulated through Cornell’s district energy system to heat campus buildings, but not so hot that it melts the pipes.
“The team was spot on with their temperature projection,” says Wayne Bezner-Kerr, Cornell’s ESH program manager.
Wayne was hired for this position in 2022, when senior leaders realized that they needed someone who could bring the ESH project to fruition. As far as he knows, Wayne is the only university-based ESH project manager in the world—a testament to Cornell’s commitment to achieve net-zero emissions by 2035.
For the first month on the job, he spent the majority of his time reading—everything from geologic characterizations of the rock profiles found in CUBO, to research on similar projects being conducted elsewhere in the U.S. and globally. Wayne says that he’s grateful to Cornell for giving him this time to ground himself.
“I'm sort of a technical problem solver,” he explains. “I've supported a lot of diverse academic research, and I've built a lot of research infrastructure. So, I've got a foot in the experimental world and a foot in the project management world, and I can speak both languages pretty comfortably.”
Lessons from our partners
Most existing large-scale geothermal projects rely on high-temperature resources, like those found in Iceland or Hawaiʻi, for example. Cornell’s ESH project is unique because it relies on a relatively low-temperature geothermal resource that underlies campus—and much of the U.S. Critically, the zones deep below campus are dry: there are no deep lakes, rivers, geysers or fluids.
One of Cornell’s external partners, Fervo Energy, has demonstrated recent success with a medium-temperature resource in Nevada. In 2023, Fervo modified technology that was used in the oil and gas industry to successfully inject water into geothermal wells to generate electricity. The Nevada project has been connected to the electric power grid ever since.
Fervo’s success has attracted tremendous attention for its potential to build geothermal systems in areas without any of the standard prerequisites: high permeability rock and abundant water deep below the ground. The project showed that a successful geothermal system could be built in ‘dry’ rock like that at Cornell.
“Fervo’s conditions are very similar in important ways to our conditions, and they showed the world how we can do this. Now, we have confidence that we can do this here, too.” —Wayne Bezner-Kerr, ESH program manager
Fervo’s approach is very similar to the plan developed at Cornell: Drill deep vertical wells that extend thousands of feet below fresh-water aquifers, then drill long horizontal extensions in a zone where the temperature is hot enough to be attractive. After the wells are lined with steel pipe, cracks in the rock are created by injecting water under high pressure. These cracks radiate for hundreds of feet around the well and become a network of tiny pathways.
Water is then pumped down one well (the injection well) and extracted from another (the production well). The total volume of rocks where water can flow from one well to another is known as the reservoir.
The key to these ‘enhanced geothermal systems’ (EGS) is careful stimulation of the rock, to optimize the density and conductivity of the cracks in the reservoir.
“If you have enough surface area, then then the flow rate along any given crack is very low—almost a trickle,” Wayne explains. “The slower the water moves, the more time it has to absorb heat.”
Fervo’s senior geophysicist, Aleksei Titov, has been consulting with the Cornell team to share their techniques and results. “Fervo Energy's project RED in Nevada has proven similar technology, significantly de risking the Cornell project,” Aleksei observes.
“ESH will serve as a powerful demonstration of the potential of this technology for the eastern U.S., further enhancing the project value and cementing Cornell University's leadership in pioneering new types of energies.” — Aleksei Titov, senior geophysicist, Fervo Energy
The next step in the Cornell project is to carefully model the subsurface conditions.
The proposed CUBO Phase 2 would consist of drilling 1500 feet deeper in the same borehole to install fiber optic cables and conduct injection tests. The fiber optics and test results will enable the ESH team to map the rock density, stress, and permeability from the top of the well to the bottom.
“Fiber optics will be installed to the bottom of the well, which will be deeper than we estimate the future reservoir will be,” Wayne says. “Thus, we can look ‘up’ at the reservoir from underneath, to better understand the subsurface conditions and observe and monitor future heat producing wells from below.”
Faith in the Big Red team
Wayne says that CUBO Phase 1 had an outstanding track record accomplishing its objectives with no safety issues or accidents. He notes that colleagues in the industry applaud the support Cornell has garnered from the local community for this low-carbon heating solution.
“It's a huge testament to the work that Sarah (Carson) and everyone else working on this project has done,” Wayne says. “We have broad support in the community. They understand the risks of climate change and are willing to think radically and creatively about how we meet these challenges.”
Cornell has involved students and faculty in doing the research for CUBO and ESH, along with a wider audience of those interested in reducing dependence on fossil fuels. Susan Petty, whom Wayne refers to as the unofficial ‘godmother’ of geothermal due to her 40 years of experience as a pioneer in the field, has followed the project closely.
“My hope is that Cornell’s efforts will lead more universities, as well as commercial and industrial campuses, to consider using deep direct-use geothermal for heating and cooling.” —Susan Petty, geothermal pioneer
Wayne feels confident that ESH will succeed in bringing a constant supply of baseload heat to campus. ESH has the lowest electrical demand of any renewable heating option, and it is the most cost-effective option.
Sarah estimates that if Cornell uses conventional heat pump technology, it could require as many as 10,000 ground source heat pump wells, plus all of the associated casing, piping, and embodied carbon. This could double the university’s electricity consumption to power them all.
Earth Source Heat (EHS) is expected to be many times more efficient than heat pumps. The relatively high temperature of the system means ESH can be used to directly heat the campus—using electricity solely to pump the hot water around. ESH also eliminates the need to rely on refrigerants associated with conventional ground and air source heat pumps. These refrigerants are among the most potent greenhouse gases.
“You can an put an air source or ground source heat pump in your home, and for every unit of energy you put into the system, you might get 3, 4, 5, or 6 units of heating or cooling out of it,” Sarah explains. “For Earth Source Heat, we think this number (the coefficient of performance) will be about 30. That’s a huge increase!”
ESH embodies the quadruple-bottom-line thinking that has made Cornell a global leader in sustainability. This framework guides decision making with an eye to the future wellbeing of people, the planet, prosperity, and alignment with the university’s purpose.
People: Cornell faculty and staff bring world-class expertise in geothermal and renewable energy technology, seismicity, geology, and the environment. Students and researchers from around the world will be able to learn from this game-changing, real-world project.
Planet: Ithaca is representative of widespread global geologic conditions—so, a solution here can be scaled around the world.
Prosperity: The ESH project can be sited on Cornell-owned property, leverage the campus’ existing district energy system, and provide significant operational cost savings over business as usual.
Purpose: Cornell has a successful history of using its campus as a living laboratory to deploy large-scale energy projects. Respect for the natural environment is a core value at Cornell.
As Cornell looks to begin CUBO Phase 2, Bill Nye is confident that the ESH project will succeed. He has faith in his beloved alma mater.
“This seems to me really a solvable problem,” he says. “We are going to figure this out if we keep messing around with this stuff. And, so, I’m excited about the future.”
Watch a short video of Bill Nye onsite at CUBO, filmed in June 2022.