Correction: A previous version of this article incorrectly stated the name of the building at the N.C. Botanical Garden that employs a geothermal heating system. The article also incorrectly stated the depth of the geothermal wells. This article has been revised to reflect the corrections. Reesenews apologizes for the errors.

CHAPEL HILL
The North Carolina Botanical Garden’s Education Center is one of the most energy efficient and sustainable buildings in the UNC system. The building saves about 50 percent of its energy solely by using a geothermal heating system.

This system is environmentally friendly because it requires less non-renewable energy and fossil fuel to heat and cool to the same degree as other systems.

It is also less expensive to operate.

The geothermal process works by heating and cooling water in a closed-loop plumbing structure.

Water from 34 wells at the botanical garden — ranging in depth from 500 to 100 feet — is circulated through underground pipes.

This well system takes advantage of consistent earth temperatures that are cool in the summer and warm in the winter relative to above ground temperatures.

From there, the water is heated or cooled based on the thermostat settings.

“There’s literally three and a half miles of closed pipes that bring water around,” said Peter White, the director of the gardens.

He explained that the water in the wells runs through a loop that goes back and forth from the building to the wells.

Essentially, the same water should be able to be heated and cooled over and over again.

“The water is not in any way used, it is just a vehicle for carrying heating and cooling,” he said.

But the system isn’t without flaws.

If the pipes start to leak the water could become acidic, but this can be easily solved by putting new water in.

Ideally, this would happen rarely and it should not happen any time soon. The system and the building it is installed in are brand new.

Jim Ward, associate director for horticulture at the gardens, said the heating system cost about a quarter of a million dollars.

Ward and White were part of a team that decided which elements of the building would be especially environmentally friendly during the design process.

After choosing to include this geothermal system, the team approached the Renewable Energy Special Projects Committee at UNC-Chapel Hill to fund it.

The money for the project came from student renewable energy fees that are allocated by the the committee.

The committee voted to fund the entire project at a cost of $210,000 in 2007, said Erin Hiatt, co-chair of the committee.

“It was appealing because it was an opportunity to establish a form of renewable energy that hadn’t yet been installed on campus,” said Hiatt.

It was also a chance to partner with the construction of a new building. The committee favors working with current construction because it lowers costs.

The costs were low during the installation of the geothermal wells because the space needed to hold the wells was accessible. The garden built them underground and covered that area with the parking lot.

The committee has funded other energy-efficient projects at the University, including installing solar thermal panels on Morrison dormitory and using B20 biodiesel fuel in the campus buses.

“They deserve a lot of credit for providing a lot of assistance here and for doing a lot in general for the whole campus,” Ward said.

This article was reported as part of the J253 Reporting and News Writing course at UNC’s School of Journalism and Mass Communication.