By Brian Crandall | January 20, 2021
It's been years in the making, but if it's successful, it would be a gigantic leap forward for renewable energy. Cornell is slowly but steadily pushing forward with its Earth Source Heat project, and hosted a community forum last night to give local residents a Zoom-based update on the plans for their East Hill campus.
If you've forgotten what the Earth Source Heat project, that's understandable. The Voice first shared news about the proposal four and a half years ago, and concepturally it's been floating around since 2009. With something this groundbreaking, these things take time to plan and time to raise the money to move forward.
On that note, we mean groundbreaking both figuratively and literally. The plan is, through a pair of wells, Cornell will circulate cool water down beneath the Earth's surface to the basement bedrock 2 to 4 miles down, where it gets heated naturally in a porous reservoir by the internal heat radiated by our planet, and then the 200°F water is drawn back up, where it can be used for heating and even electricity production. The carbon-free project is considered an "enhanced geothermal system" (EGS), since the subsurface reservoir is man-made. Think of it as similar to the Lake Source Cooling project, but backwards.
For the comparably modest impact of building the wells and energy infrastructure, the project could have an enormous impact on reducing Cornell's carbon emissions - the savings from using enhanced geothermal vs. conventional energy sources could save up to 82,000 metric tons of CO2 from being emitted into the atmosphere each year, 8% of the county's emissions and 38% of Cornell's.
The thing is, this is all fairly new and unexplored technology. It's only been in the past decade that this even been feasible outside of geologically favorable regions like Iceland and some parts of the Western United States. If Cornell can demonstrate it's feasibility and really make some headway with this enhanced geothermal system, it could be put into use in many parts of the Appalachians, and potentially in similar locales around the world.
The United States government recognizes the potential. Last August, the university secured a $7.2 million U.S. Department of Energy grant to cover some of the initial costs of drilling the 2-mile-deep exploratory borehole and create what Cornell calls "a state-of-the-art observatory" that will allow scientists at Cornell and other institutions to study the physical, geological and seismic characteristics of the rock far beneath the campus. The borehole, which be drilled on Cornell property, will be used to assess the Earth Source Heat project's feasibility, and if it looks good financially and structurally, they can continue designing the geothermal circulation system
Since the project was announced, Cornell has already conducted some seismicity studies, to help ensure the project is not at risk of earthquake damage or potentially triggering an event. Last January, the university invited research groups to submit experiments and studies for the borehole, to enhance its scientific value, and by extension it makes for an easier sell when pursuing future federal grant funds. Deep boreholes like this are not unheard of, but they're typically done by industrial firms who aren't inclined to give access to proprietary data. They also aren't usually this deep, as the layer with fossil fuels lies between the surface and the heat reservoir Cornell plans to drill down into.
For last night's virtual community forum, the university selected Rick Burgess, vice president for facilities and campus services and co-chair of the Sustainable Cornell Council; Engineering Professor Terry Jordan, lead Facilities and Campus Services Earth Source Heat engineer Steve Beyers, and Engineering Professor Emeritus Tony Ingraffea. The forum and Q&A was moderated by Joel Malina, Cornell's vice president for university relations.
As explained by the panel, the borehole and its support facility, officially called the Cornell University Borehole Observatory (CUBO) will be about three feet wide at the surface, but progressively narrower as it presses deeper into the earth. As designed, the CUBO well will have five layers of steel casing, with hefty amounts of concrete around the casings to ensure borehole integrity and to prevent impacts to surrounding groundwater. Ingraffea, a locally well-known anti-natural gas fracking and renewable energies advocate, added that in comparison, natural gas fracking uses only two casings and as little concrete as they can get away with. Drilling mud chemicals would be used, but not shale gas fracking chemicals. "It's only what's necessary in the drilling mud, and those are know to be non-hazardous, non-carcinogenic materials; water, (and) bentonite (absorbent clay)."
The borehole would contain a fiber optic cable as part of the monitoring of the structural stability of the hole, as well as a very sensitive seismometer and a thermometer to check temperature as the borehole advances - to be successful, the ground would need to exceed at least 70°C (160°F). However, it's not just temperature that's important, but sustainability of the heat deep in the ground. While those involved in the project have a rough idea of what they expect, drilling through three generalized sedimentary rock layers before reaching a basement rock similar to that found in the Adirondacks, the truth is they aren't 100% sure how it's structured. They don't know how hot or fractured the rock is two miles down. They don't know how the existing subsurface fluids flow, what's potentially mixed in those fluids, or how introduced water would flow through the rock. They don't have a strong grasp of what the overall temperature gradient with depth looks like. These are features that are key in designing the Earth Source Heat system, and they're details that Cornell hopes to have a much better understanding of with the CUBO well.
The facility itself would be sited on the eastern end of Cornell's campus lands in Cornell's warehouse and storage complex off Dryden Road/Route 366. The borehole site is currently a gravel lot used as a contractor's yard. The location was chosen because it's away from local aquifers, and there are few neighbors nearby for whom the drilling could pose discomfort. Well monitors would be places around the borehole site, and seismometers would analyze the structural impacts of the deep drilling both near the site and further out into the county.
In response to a question from Dryden's Hillary Lambert, Ingraffea stated that the amount of water used would be comparatively modest when compared to something like a fracking operation - the exploratory borehole only uses water in the drilling itself, and a potential ESH system would be a closed loop, meaning that there should be very little if any loss. A modest amount would be use to break up the rock down in the reservoir if it is not permeable, but Ingraffea stressed it would not be anything on the scale of the water used and polluted with chemicals in fracking. There may be some fracking, though not with the scale and chemical mix of natural gas fracking; the hope is that they won't need to do any due to natural cracks and pores in the rocks two miles down, which once again, is something they hope to use the CUBO well to figure out.
In response to another question from Lambert, Byers added that the permits and approvals process would involve the NYS DEC's procedure for stratigraphic well permitting, and any above-ground structures would likely involve municipal review, most likely the town of Ithaca given the location.
As for costs, it'll be a pretty penny. Beyers estimates the infrastructure would cost in the tens of millions, though the estimated costs for heat distribution once implemented are expected to be on par with the price of commercial natural gas, about $6 per million British thermal units (mBTUs). At his point, the focus is more on the CUBO facility for the next couple years, to make sure the system will even work before they start pricing out all the infrastructure.
Also, don't think this will happen overnight either. The CUBO well exploratory phase would be about 3 years. Implementation of the full-scale Earth Source Heat system could take another five years if the project proves to be feasible and remains viable, at which point we're around 2030, and may make or break Cornell's ability can achieve its goal for a carbon-neutral campus by 2035. Unfortunately, permitting is arduous, the costs are high, and this is uncharted territory in terms of geothermal systems, as this is much deeper and in a much more marginal environment than a volcanic hotspot.
The exploratory hole is still in the planning stage, but the hope is to have designed, planned and permitted by this fall. It's a gamechanger, if it can be proven to work. The university is excited if still somewhat unsure it'll work, and we'll have to wait and see if their effort to take a giant leap forward in geothermal energy pans out.