Courtesy of Cornell University

August 31, 2022

The Science Behind Cornell’s New Sustainable Energy Initiative: Earth Source Heat

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On June 20, the Cornell Borehole Observatory began drilling into the Earth. Their goal is to reach a deep depth where there is natural heat sufficient to heat all of campus. While this new technology has a ways to go before providing electricity for every home across the country, Cornell has taken a huge leap towards a sustainable future.

With a limited supply of fossil fuels, the University has explored alternative energy options. In 2009, the University set its sights on using Earth Source Heat, a sustainable type of geothermal heat that rests deep underground, to heat the campus. 

This is  part of the University’s Climate Action Plan to reach carbon neutrality — the amount of carbon used and emitted equaling the amount of carbon that gets absorbed from the atmosphere — by 2035. 

“Due to the planet’s core radiating out from deep within the Earth and other secondary mechanisms like radioactive decay of elements in rock materials, local heat fluxes occur in certain areas of Earth’s crust,” Adam Hawkins, a chemical and biomolecular engineering postdoc, said. 

The University plans on harnessing and distributing ESH across campus as an alternative to traditional energy sources, such as oil or coal, because other sustainable energy sources, such as water, require electricity to be maintained.

“All we have to do is drill a few holes and we can produce essentially unbounded energy for millennia,” Hawkins said.

The University will utilize the natural heat from the ground to heat water that is then carried and distributed around campus through pipes and wells.

Three things are needed for this to take place: Optimal heat, permeability and water. Water will heat up by exchanging thermal heat with the Earth and this heat gets circulated in a sustainable fashion.

The perfect spot would be about 3000 meters deep at around 60 to 90 degrees Celsius and very permeable. 

Water is an excellent heat conductor because of the way that hydrogen atoms in one water molecule can form temporary bonds with oxygen atoms of another water molecule, creating hydrogen bonds. 

Hawkins stated that the reason why New York State hasn’t switched to ESH is because of factors such as differences in geology and subsurface conditions that make it harder to use commercially. However, places with high volcanic activity are actively using this technology

To overcome this local hurdle, the University created the Cornell University Borehole Observatory

Prof. Larry Brown, earth and atmospheric sciences, used his skills in seismic methodologies for exploring the subsurface, to ensure CUBO drill site would reside in an optimal location and subsurface conditions. This is very similar to how oil companies plan a drill site.

Brown explained that by vibrating the earth surface, soundwaves are produced and these echo off differing rock layers, creating a three dimensional rendering of the unique geology.

“Seismic reflection surveys are used to image the rock layers and to look for possible problems such as pre-existing fault zones and pockets of natural gas,” Brown said.

These procedures are usually contracted out, but Cornell had the opportunity to make it into a learning opportunity for students, with many getting to witness and assist in these seismic surveys.

The site was chosen due to its proximity to campus and minimal disruption to campus life. The next step was to determine what properties lay nearly two miles below Earth’s surface. Every week, it drills about 200 feet deeper and is then cemented and measured. 

“The reason for this pilot study was to test the feasibility of this type of project, it being the first of its kind for the region, to determine what we have before we take the next steps,” Prof. Brown said.