New geothermal system for MSU’s Romney Hall

By Marshall Swearingen MSU NEWS SERVICE

BOZEMAN – Above ground, Montana State University’s historic Romney Hall is being transformed into a home for high-impact student programs and much-needed classrooms, but underground, one of the biggest energy conservation projects in university history is also beginning.

The Romney Oval, open space situated directly north of Romney Hall, will be underlaid with about 80 boreholes that will anchor a high-efficiency geothermal energy system serving Romney Hall and eventually several other nearby buildings.

“This geothermal field will make Romney Hall a leading energy performer at MSU and in the state,” said Dan Stevenson, associate vice president of University Services. The system will allow the 98-year old Romney to use less than half as much energy per square foot as other MSU buildings such as nearby Reid Hall, he said.

By enabling a more efficient heating and cooling system for several campus buildings and reducing reliance on MSU’s natural gas-fired steam heating plant, the geothermal boreholes are projected to reduce MSU’s associated carbon emissions by 1 million pounds per year, or about 20,000 metric tons over the lifetime of the system, Stevenson said.

“Establishing major energy conservation assets like this geothermal field and combining those with strategies like solar heating and sharing energy between buildings will allow MSU to become one of the most energy-efficient campuses anywhere,” Stevenson said.

The geothermal boreholes—each 700 feet deep and 7 inches in diameter—will consist of closed loop water pipes encased in a special grout. Together, the boreholes will act like a giant battery for storing heat extracted by Romney Hall’s ventilation system when the building is being cooled. The boreholes will also store heat captured by a “solar wall” that will convert sunlight to heat on the building’s south face. The water circulating in the boreholes warms the surrounding earth by only a few degrees, but devices called heat pumps can later concentrate the stored energy to warm the building.

“We think we’ll be able to heat Romney almost entirely with the geothermal system and the solar wall,” with very little need for heat from the central campus heating plant, Stevenson said. The main energy input will be efficiently used electricity to power the heating, air-conditioning and ventilation units throughout the building, he said.

Romney’s geothermal system will connect with the one at Norm Asbjornson Hall, nearly doubling the size of that heat battery and creating what’s called an energy district. As other nearby buildings are upgraded, they too can connect to the system to reduce energy demand, Stevenson said. MSU pioneered that approach during its biggest energy conservation project, a multi-phase effort in 2011-2015 that was integrated with the construction of Jabs Hall. The Jabs geothermal system serves a total of four MSU buildings and has reduced energy costs an average of $130,000 per year.

“We’ve really reached a tipping point with these energy districts,” Stevenson said. “We’ve proven how effective they can be, and we’re looking to expand this concept all across campus. MSU is a pioneer in this type of large-scale geothermal system, and our projects can serve as a model for similar systems worldwide.”

In preparation for constructing the boreholes, two pilot holes were drilled to assess subsurface conditions. A plan was developed for upgrading large sewer and storm water pipes serving adjacent buildings while doing the earthwork for the geothermal system, Stevenson said. The plan includes adding new paths and landscaping to the Romney Oval. A number of trees need to be removed for the valuable project, but for every tree removed the university will replant a new one, he said, adding that the long-term benefits of the project are significant, and careful consideration has been made regarding the short-term impacts to the space.

“This is an incredibly important project for the future of MSU’s energy infrastructure and sustainable energy design everywhere,” Stevenson said of the Romney geothermal project.