New, cutting-edge geothermal technology significantly cuts energy costs and protects the environment
March 8, 2024
Kraus-Anderson using new system on several Minnesota construction projects
Geothermal energy has been used for a good long time. Humans have used thermal energy for 10,000 years; Icelanders enjoyed geothermal baths in the Viking Age; and U.S. commercial buildings introduced geothermal systems 75 years ago. Over time systems have continually evolved, helping building owners save energy costs.
One such advancement, introduced by New Brighton, Minn.-based Darcy Solutions, is new, cutting-edge geothermal technology. Darcy is a cleantech startup founded by University of Minnesota geologists focused on advancing and deploying geothermal technology.
The improvement from earlier geothermal systems is that the new Darcy system works with groundwater, using its superior thermal properties to heat and cool industrial and commercial buildings with improved efficiency.
Geothermal technologies are the most energy efficient solutions for heating and cooling and are recommended as the number-one solution by the Department of Energy. But the technologies are only now beginning to see broader adoption.
“In the broadest strokes, digging into the earth to tap the moderate and stable temperatures underground is a much more energy efficient way to heat and cool buildings,” said Matt Stringfellow, Kraus-Anderson’s mechanical and electrical systems group manager. “The sustainable technology is an improvement over earlier geothermal systems because the number of wells required compared to standard geothermal is significantly reduced. In addition, the heat exchanger down inside the well is a new and prominent application aspect.”
A standard individual geothermal well can typically provide one to two tons of cooling capacity. An individual Darcy geothermal well provides between 60-150 tons of cooling, depending on site geology and ground water availability. “This efficiency can slash the number of wells on a project site by 20-50 times, significantly reducing the amount of drilling needed on projects which saves time and can lower costs,” added Stringfellow.
Kraus-Anderson projects using new technology
As of January 2023 there were only a handful of systems in operation in Minnesota. Kraus-Anderson is currently coordinating the new geothermal heat pump technology on several projects: Jefferson Elementary and Washington Kosciusko Elementary for Winona Public Schools, expected to be completed in September 2024; and the Woodbury Central Park project for the City of Woodbury, slated to begin in April 2024 and completed in 2025.
The existing Winona school buildings are being renovated with all new mechanical systems. The cooling load for each building is approximately 300 tons.
“For example at Jefferson Elementary, the building needs only two individual Darcy geothermal wells to cool the entire building and five individual Darcy wells to heat the entire building.
Standard geothermal would have required 200-300 individual wells to cool each building and 400-600 individual wells to heat each building,” said Stringfellow. “This is a substantial saving.”
In addition, a big driver for geothermal solutions for state-funded projects is that it is often the only way to meet the energy requirements for the mandated B3 Sustainability Guidelines.
“Darcy’s breakthrough design delivers practical, cost-effective and sustainable heating and cooling. The technology doesn’t burn fossil fuels and also reduces greenhouse gas emissions, protecting the earth’s natural resources and the health of our environment for future generations,” said Stringfellow.