Passersby near the Sunken Garden and Richmond Road may be wondering what on Earth is happening behind Monroe Hall. Technically, though, it’s what’s within the Earth that matters.

As part of the Housing and Dining Comprehensive Facilities Plan, William & Mary is actively installing a geothermal system that will efficiently and sustainably heat and cool Monroe Hall. The system will be up and running when students return to the building in 2024.

Monroe Hall is the first structure at the university to connect to a geothermal system, but it won’t be the last. Old Dominion Hall is also scheduled to receive a geothermal system, and an extensive geothermal field will be constructed to serve all of the new housing and dining facilities under development for the West Woods. The Old Dominion and West Woods projects will be completed in 2025. Later phases of the plan will also incorporate the use of geothermal energy.

Work on the housing and dining facilities plan started this summer. Over the course of the next decade, the university will renovate or replace 80% of its campus residences and add two new dining spaces to the campus. The geothermal systems that are part of that plan support W&M’s Climate Action Roadmap.

“Bringing the buildings onto a geothermal system will allow us to take the buildings off of the central utilities for heating and cooling, which eliminates the need to burn natural gas,” said Dan Pisaniello, university architect and director of facilities planning, design and construction. “It’s incredibly energy efficient and environmentally friendly, and it plays to the university’s sustainability goals. This is a significant move and the precursor to many other projects that are going to use geothermal energy.”

In addition to boosting energy efficiency, the transition to geothermal systems will significantly cut costs.

“We expect these systems to reduce our consumption of electricity and operating expenses in these facilities by approximately 30%,” said Sean Hughes, interim associate vice president for business affairs.

What is geothermal energy?

“In Williamsburg and most places, the temperature gradually increases as one goes deeper into the earth,” said Christopher Bailey, professor and chair of the geology department. “The bulk of the heat increase is a result of small amounts of radioactive elements in rocks and sediment. As these elements decay, they release heat. Rocks are slow conductors of heat, so heat increases with depth. The rate at which it increases is determined by the type of rock present, because some types of rock are more radioactive than others.”

Natural geothermal displays include geysers, hot springs and mud pots.

Human use of geothermal energy is both ancient and cutting edge. Archaeological evidence indicates that some Native American tribes used geothermal heat for cooking as early as 10,000 years ago. Scholars relaxed in hot springs in central China more than 2,300 years ago, and warmth from geothermal sources heated living spaces in the ancient city of Pompeii as far back as 2,000 years ago.

Historically, the use of geothermal energy required a geographic location in close proximity to heat pockets near the Earth’s surface, but modern technology allows people to access the heat that consistently emanates from deeper rock and sediment.

Bailey explains how modern geothermal systems interact with subsurface environments. “Williamsburg, located on the Atlantic Coastal Plain, is underlain by layers of sand, silt, mud and gravel,” Bailey said. “In this environment, when water is slowly circulated to depths of less than 100 meters, it acquires the ambient temperature of the subsurface. These temperatures range from approximately 55 to 70 degrees Fahrenheit. Via heat exchange, the water can be used to both cool and heat buildings. These systems have high upfront costs, but should function without significant maintenance for decades.”

This boils down to improved energy efficiency and a decreased carbon footprint without compromising the aesthetics of the campus.

“After the wells are installed, the system will be invisible,” said Maggie Evans, associate vice president for student affairs. “As we get closer to occupancy, we’re going to add subtle signage or other information in the building that lets the students know what’s behind walls and what’s underneath the ground so that they can better understand the engineering, planning and design of the project, as well as how it benefits them in their daily lives.”

Pisaniello points out that this project also embodies the W&M spirit of the ampersand. “Monroe Hall is one of our 1920s Georgian Charles Robinson buildings,” Pisaniello said. “Even though it’s almost 100 years old, it’s going to be modern and new and amazing as a living space, but still speak to history. At William & Mary, we talk about the importance of the ampersand. In this case, it’s history & modernity, tradition & innovation. It’s a perfect example of that important aspect of the university.”

, Research Writer