Written by Sustainability Outreach Intern Helen Deng '26
The Massive Hole™️, aka climate action in progress. Photo credits: Chris Johnson
Navigating construction around campus daily as a student, this was one of the main questions on my mind. But this summer, as a Dartmouth Sustainability outreach intern along with Alex Campbell ‘26, we got to learn more about how that giant hole in the ground actually plays a crucial part in Dartmouth's climate goals.
In 1898, the steam plant was constructed—the last time our campus's energy production infrastructure was majorly overhauled. Fast forward a little over one hundred years to 2024, and we are now witnessing the milestone transition to clean energy, navigating the construction dust in our everyday lives.
As the climate crisis intensifies, our campus is doubling down on our energy transition. On Earth Day of this year, Dartmouth announced its historic Climate Collaborative initiative. President Beilock pledged to decarbonize campus operations by 60 percent by 2030 and 100 percent by 2050, backing it up with a $500 million investment to make it happen. Decarbonization includes major upgrades around campus, such as improvements to energy efficiency, renewal and insulation of residence halls, the continued transition from steam to hot water heating, and the installation of geo-exchange borefields and high-capacity heat pumps in order to "aggressively reduce our greenhouse gas impact."
The sheer scale of the infrastructural endeavor to decarbonize blew my mind, and I realized a closer look at the construction site was an incredible opportunity. Despite all the dust of a construction site, who could pass by our once-in-a-century chance to get close to this historic moment? Organizing a tour of the decarbonization site as part of my internship was the perfect chance to expose students to the massive transition happening beneath our feet.
This summer, on August 8th, it became a reality. Around ten students had their interest piqued and joined our tour of the construction site at the edge of the Athletics district. To the untrained eye, the view seemed like a maze of pipes, dust, construction vehicles, and fencing—perhaps not much to see.
In fact, it was a section of construction for a major distribution piping upgrade on East Wheelock Street, a crucial part of the larger geo-exchange system. Steam pipes – an outdated, inefficient mode for transmitting energy – were being replaced with vastly more efficient hot water pipes, which will boost our campus energy efficiency by an anticipated 20 percent.
Decarbonization Construction Map. Source: Decarbonization in Progress | Campus Services
Director of Sustainability Rosi Kerr said, "When we turn our attention over here, that not-that-exciting looking hole is the beginning of something very exciting, which is radically changing how Dartmouth distributes energy, changing how Dartmouth generates energy, and changing how Dartmouth uses energy."
It’s no wonder that encountering construction was part of my morning routine this summer—as part of the project’s timeline, regions surrounding East Wheelock Street, Fayerweather, Ivy Lane, and south of the Alumni Gym were affected by piping upgrades. This encompassed the entire first half of the path I walk on daily to class, as do many other students who live on the east side of campus. It’s not over yet! In the next decade, the construction is planned in phases to minimize disruptions; the complete transformation of Dartmouth’s energy infrastructure doesn’t happen overnight.
District map: Geo-exchange borefields will work alongside heat pump plants that can move and store the heat captured by the geo-exchange system. The districts on the map represent groups of buildings that will be heated and cooled by the geo-exchange system as each geo-exchange plant comes online. Source: Dartmouth Decarbonization.
The big picture plan: the underground piping and electrical ducts installed this summer will connect to a heat pump plant, which will be powered by a series of borefields with hundreds of 800-foot-deep wells that use the subsurface of the Earth as a thermal battery.
On our tour, Mike Witzing, an energy project engineer, explained, "The ultimate goal of this program is to eliminate the burning of fossil fuels [... We will] eliminate the oil fired steam boilers, and replace them with heat pump plants."
As we turned our gazes to the construction site before our eyes, we were looking at the first step of this big picture: building a distribution piping network to move water from the heat pump plant all around campus, transitioning away from steam.
Gesturing back at the pipes in the site, Mike explained that they will be circulating water from our heat pump plant, which generally pumps cold water during the summer and heats hot water during the winter to suit our needs. After a basic explanation of how heat pumps work, we learned that the ones being built on campus are large-scale ground source heat pumps, which are much more efficient than your typical small-scale air source heat pump. These large-scale ground source heat pumps require connecting to the aforementioned geo-exchange borefields, which our plan to build is by drilling holes under the earth, putting down pipes, and circulating water, in order to exchange heat with the earth—all connected back to the heat pump plant for the water to then be distributed to heat or cool buildings.
On top of replacing underground piping, all campus buildings currently running on steam have to be converted to hot water distribution. The transition from steam to hot water heating is included in Dartmouth's housing renewal plan, renovating undergraduate residence halls such as South House's Fayerweather buildings (or the "Fayes," as we students know them) to include critical updates. Mike noted, “There are 90 or 100 buildings where we're going in systematically, year by year, taking out the steam heaters and replacing those with ones that will use the hot water."
A close-up view of the construction site, where efficient hot water pipes are replacing antiquated steam pipes. When completed, the shift from steam to hot water will result in approximately 20 percent energy savings across campus. Photo credit: Chris Johnson.
During the tour, we discussed issues I had barely thought about before—peak demand and energy resiliency. Managing the peak demand of the year due to our climate is a major challenge that some of our peer institutions don't have. Rosi explained that Dartmouth's climate means the demand is extremely peaky, with higher loads in summertime and wintertime: "We have a big difference between our lowest demand day and highest demand day. When you're building for geo-exchange, you want to build for the base load day, not for the highest demand day. As those last units are very expensive, it ends up becoming inefficient to get to the highest load. That's one of our most interesting questions: How do we manage that peak hour of the peak day of the year?"
I also learned about the importance of ensuring electrical resiliency, including implementing back-up electrical generation, through Rosi's story of her experience as a senior at Dartmouth when an ice storm caused a blackout in the area and a backup generator powered by oil kept our campus's lights on. Now that Dartmouth is moving towards clean energy to combat the climate crisis, figuring out how to create electrical resiliency in a low-carbon way is crucial, especially as the grid gets older. Sustainability Assistant Director Marcus Welker added, "One of the other technologies that Dartmouth is exploring is storing energy from the summer to use in the winter to help us get over those really cold days. Part of that is installing solar thermal systems. It's another piece of the puzzle on how to deal with those very cold days, and how to use the heat that we do have available in the summer to use in the winter."
When asked what he finds to be the most interesting part of this project, Mike answered, "The heat pumps are exciting because it's new technology. But to be honest, the most interesting thing is how everything has to be coordinated together—not just physical coordination, but temporal. It's a huge challenge. Just something as simple as this, we have to coordinate the construction with when occupants need to be inside the building, so we have limited windows of time. Imagine having to do this across the whole campus, not just with pipes, but with building conversions, with the borefields, with the heat pump plant. That's the part I find really challenging and exciting and interesting on this project—so many interconnecting pieces."
One information-dense hour later, I came away knowing much more about the state of our campus energy infrastructure. From open-cut trenches to horizontal directional drilling to ground source heat pumps, we learned about a dizzying array of construction techniques, the different pipe distribution systems, and challenges of campus energy resilience – a veritable masterclass in the critical issues shaping the energy transition everywhere, grounded in the microcosm of Dartmouth. As an environmental engineering student myself, I was deeply fascinated by the logistics behind the whole endeavor, learning about construction concepts through components being poured and built right in front of my eyes.
Students hear from project engineer Mike Witzing and Director of Sustainability Rosi Kerr. Photo credit: Helen Deng '26.
One of the main challenges of sustainability transitions is that it can be difficult to make benefits visible when most people are not able to see or get close to the moving parts; infrastructure is often behind a giant construction fence or wall, pipes are buried underground, and any number of construction obstacles bar transparency. As Rosi explained, "These next five years of construction are a really great opportunity to literally open some of that up."
Ultimately, this tour was an incredible opportunity for us to open up the mystery and get behind the green construction fence. It was a stepping-stone bridge between theory and practice that environmentally-minded students like me crave: bringing together knowledge we learn in the classroom with the real world, on-the-ground, physical reality of building the infrastructure required to put our words into action.
For more information on Dartmouth’s energy transition timeline, construction updates, or other project details, check out the Dartmouth Decarbonization website!
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