College blows off steam to help power campus
Rather than replace coal-fired boilers, one university opts for an ambitious geothermal system.
Gazing at an empty soccer field here at Ball State University, Jim Lowe explains his vision for converting it into a field whose harvest would supply this entire campus with renewable geo-thermal energy.Skip to next paragraph
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That vision is becoming reality. This month Mr. Lowe, the university’s director of engineering, gave the go-ahead for diesel-belching drill rigs to begin punching 400-foot-deep geothermal wells through athletic fields, parking lots, and grassy lawns across this leafy campus.
Parts of the school may temporarily look like oil fields – until earth is eventually smoothed back to cover the wells, Lowe says. But by transforming the state’s third-largest university into a pincushion, Lowe – with the backing of Ball State President Jo Ann Gora and the university board – expects to shift the school’s energy profile into the 21st century.
Hundreds of colleges across the United States have in recent years pledged to “go green” with energy use and reduce carbon emissions. Some have put up solar panels or wind turbines. Just a few score campuses today use geothermal energy – mostly for heating and cooling isolated buildings.
What makes Ball State’s geothermal plan audacious is its size: 3,750 to 4,000 wells will be dug to supply heating and cooling to most (more than 45 of 50-plus) buildings on the 660-acre campus.
“Ball State’s geothermal project is clearly going to be the largest heat-pump complex in the nation,” says John Lund, director of the geoheat center at Oregon Institute of Technology (OIT) in Klamath Falls. “These larger projects may be something we’re going to see more of in the future.”
Not to be confused with “direct use” geothermal that uses boiling water pumped to the surface from deep below ground to drive generators or supply space heat, Ball State’s program uses “little G” or “ground source” geothermal energy – the natural temperature of the near-surface earth.
“What we’re realizing is that the ground itself is really an energy bank,” Lowe says, “and we can make withdrawals from it that help heat and cool the entire campus, saving us money and helping the environment.”
A close (15 feet apart) pattern of five-inch-diameter, 400-foot-deep wells will be tattooed into three well fields on campus. Into each will go two loops of polyethylene piping – one for cold water, one for warm.
In winter, cold water will flow to the fields and down the wells to absorb heat from the surrounding earth, which stays in the 54- to 55-degree F. range year-round. Water warmed by the wells will flow back to a heat exchanger that collects and concentrates the warmth to heat buildings.
To cool those same buildings in summer, the process reverses: Water warmed by the heat exchanger is cycled into the wells, where it is cooled by the surrounding earth.
While pumping all that water requires electrical power, the thermal energy harvested by the system is four times greater than the energy the system consumes. Overall, the project will save an estimated $2 million
annually in fuel costs while halving the campus’s yearly carbon dioxide emissions – an 85,000-ton cut.