A new elementary school has carried Cobb County into the forefront of the “green” building movement.
Parents at East Side Elementary School pushed for an energy-efficient school when it came time to rebuild, and officials listened. But saving money, rather than environmentalism, was the main motivation behind the heating and cooling system they selected.
The new geothermal system uses the Earth’s constant temperature to condition the air. It cost extra but is expected to pay for itself in a little more than a decade. If it works as planned, more geothermal systems could be installed in future schools, with a potential savings of millions of dollars a year.
“I have no doubt whatsoever that we’ll save $40,000 a year on electric bills [at East Side],” said Gene Trull, the energy coordinator for Cobb schools.
During the heat wave in August, just after the rebuilt East Side Elementary reopened on Roswell Road near Marietta, its energy bill was about $13,000. While that’s more than the nearly $11,000 it cost to cool the old building in August 2010, the new building is double the size.
This is the Cobb County School District’s first experiment with the novel technology. None of the other major metro school districts, with the exception of Atlanta, have tried it.
The system added $585,000 to the $15 million construction project, most of the money going into the ground: A contractor spent three months digging 110 wells on the property and laying 44,000 feet of plastic pipe. Each well is about a half-foot in diameter and 400 feet deep and contains a water-filled pipe that loops down into the earth and back into the building.
It’s just below 60 degrees that far down, and the pipes enter the building at about that temperature. They cool the air on hot days and heat it on cold days. From there, smaller conventional systems bring the temperature to an ideal level at a big savings in energy costs.
Geothermal is becoming more popular in the Southeast, said Mackinnon Lawrence, a senior analyst with the clean technology market research firm Pike Research. He said the installation cost is a deterrent for some but that the systems pay for themselves over time. “It’s really just a straight budgeting thing if you can get past the upfront cost,” he said.
Geothermal is 1 percent of the heating and cooling market, but more institutions are turning to it as they learn about it, he said. Geothermal heat pump shipments grew from under 36,000 in 2000 to more than 115,000 in 2009, according to the U.S. Energy Information Administration.
Officials with the school systems for DeKalb, Fulton and Gwinnett counties said they have no geothermal systems in their schools. Only Atlanta Public Schools has tried the new technology, installing it at Springdale Park Elementary, which opened on Ponce de Leon Avenue two years ago. Jere Smith, a school system finance official, said geothermal made sense because the site had minimal granite to drill through and because geothermal eliminated the need for a noisy and high-maintenance cooling tower, which might have irritated nearby homeowners.
Private schools were years ahead on the technology. Woodward Academy in College Park installed its first geothermal system eight years ago and then added three more. The systems cut the energy bill by a third and pay for themselves within five years, spokeswoman Marci Mitchell said. School officials are considering a fifth geothermal system.
Mount Vernon Presbyterian School in Sandy Springs spent an extra $350,000 to build a geothermal system into its new building six years ago, and it’s already paid for itself, said Bruce Morine, the school’s chief financial officer. “It saves us about 40 percent on our electric bills,” he said.
The systems are typically invisible. The 50 wells at Mount Vernon are buried under a football field. At East Side, the wells are under a parking lot. The only evidence of a geothermal system is the valve-studded pipes in the mechanical room.
“I have not noticed anything different, and I guess that is a good thing,” principal Elizabeth Mavity said. She said parents pushed for a “green school” and were mostly happy with what they got. But she was wary of the new heating and cooling system when the school year started. The concern was unwarranted, she said.
“The temperature has been perfect.”
About the Author
