Carleton College plans
for carbon neutrality
team is confident it will be reached thanks
in part to the executable vision provided
in Carleton’s Utility Master Plan.
INVESTED IN SUSTAINABILITY
Carleton was founded in 1866 as a
liberal arts college, but early on, campus
leadership expanded its perspective to
include an environmental focus. What
started in the 1920s with an 800-acre
arboretum has led to an investment in
wind turbines, solar energy, progressive
campus infrastructure upgrades, a robust
environmental studies program, student-led organic farming, multiple student
environmental organizations, and numerous studies and plans to evaluate sustainable options for energy and waste.
Since 1910, the Carleton campus has
been served by a central steam plant,
which today houses three steam boilers with a combined capacity of 110,000
lb/hr. The 330 F saturated steam is distributed at 80 psig to 1. 6 million sq ft
of space in 36 buildings via a network
of both direct-buried, ductile-iron piping and welded-steel lines in tunnels. A
chilled-water system ( 1,950-ton capacity) was also installed at the plant in the
1980s, currently connected to 20 buildings representing 850,000 sq ft. (In addition, two college-owned wind turbines
generate up to 1. 68 MW of power. One
turbine directly serves 25 percent to
30 percent of the campus demand while
the other supplies the public grid.)
Last summer, as the rumbling drill rigs repeatedly pierced the iconic ground of the grassy “Bald Spot” in the heart of campus, Carleton College students
were intrigued by the transformational
Utility Master Plan that was stitching
together the subterranean geology underfoot. Passersby curiously pondered what
was going on and why. Disruptive construction and a major utility system overhaul might seem like a nuisance, but at
Carleton, south of the Twin Cities in Northfield, Minn., it was a milestone. Geothermal bore fields were being installed as
part of a new hot water heating system,
which will help lower emissions. By 2050,
the campus will be carbon-neutral. That
may seem a lofty goal, but the leadership
Courtesy Carleton College.
Leighton Hall, Carleton College, Northfield, Minn.
Drilling in a geothermal field on the Carleton College campus, summer 2018.
Courtesy Carleton College. The Carleton campus has been supplied with
steam for heating since its central steam
plant was built in 1910.
Courtesy Carleton College.
A new geothermal district heating system will lower
emissions and operating costs.
Martha Larson, CEM, Manager of Campus Energy and Sustainability, Carleton College;
and Lee Tapper, PE, CIAQP, LEED AP, Senior Mechanical Engineer, MEP Associates LLC