We think of geothermal power, we think of geysers and bubbling, boiling waters that can be tapped for utility-scale electricity production. But there’s a very different world of geothermal power, where onsite implementation can yield water-heating and air heating and cooling, and nowhere is it more clear than at Ball State University in Muncie, Indiana.
There, the nation’s biggest ground-source, closed-loop geothermal heating and cooling system now is about to get bigger.
University trustees backed completion of the second phase of a geothermal project that when completed – in 2015, according to plans – will save $2 million a year while halving the university’s carbon footprint as it continues to reduce its reliance on old coal-fired boilers.
“We have written the book on large-scale geothermal installations, and we already are seeing the cost savings from the project,” Randy Howard, vice president for business affairs and treasurer, said in a statement.
Systems like the one at Ball State make use of the stability of Earth’s temperatures not far underground. In the winter, a geothermal heat pump transfers available heat up; in the summer, the system transfers heat underground.
To implement the first phase of the project the university drilled 1,800 boreholes around campus, each 4 to 5 inches in diameter and 400 to 500 feet deep. These holes, and the additional 1,800 needed for phase two, were then covered, topped with parking lots and recreational fields. One thousand miles of piping circulates water in a closed loop system, and facilitates the heat transfer between the ground and the buildings.The separate hot and cold pipe systems eventually pass through heat exchangers and fans that blow either the hot or chilled air into the buildings.
The second phase, which has already been under way, will double the number of boreholes. The new appropriation will pay for that work as well as modifications to accommodate new chillers, hot and chilled water distribution looping and modifications of the remaining buildings to accept the geothermal connections, the university said.
Ball State had been aiming to finish the geothermal project by March 2014 to meet EPA emissions regulations related to its boilers, but needed $30 million to do the job. That funding finally came through earlier this year.
According to the Ball State Daily News, “The geothermal facilities will replace (a) World War I vintage generation facility, which emits roughly 85,000 tons of carbon dioxide annually.”