July 21, 2008
Campus carbon offsets eyed
By Carol Clark
Could selling carbon offsets help create more renewable energy at Emory? The Office of Sustainability Initiatives is investigating that possibility, building on preliminary research conducted by Julie Mayfield ’96L, the University’s second sustainability scholar-in-residence.
“There are several promising areas for renewable energy on campus,” says Mayfield, who served as director of Emory Law’s Turner Environmental Law Clinic for four years.
Mayfield researched renewable energy projects at universities throughout the country, then met with key people within Emory’s Facilities Management. Based on the data she gathered, she recommends that Emory consider pursuing more in-depth, technical analysis of the following possibilities:
“It’s an efficient technology for heating a large body of water like a swimming pool,” Mayfield says, adding that it requires a sizeable investment to install solar-thermal arrays to heat a pool, such as the one in the Woodruff P.E. Center. By one estimate, it could take 17 years to see the payback for the energy savings.
“This technology takes advantage of the Earth’s fairly constant cool temperature to reduce energy use by heating, air-conditioning and ventilation systems,” Mayfield explains. Water is pumped through pipes that are installed several hundred feet below ground. As the water moves through the pipes, it is naturally cooled to about 50 degrees. When that water comes back to the building, it helps lower air temperatures within buildings during the warmer months. Conversely, in winter the water is warmer than outside temperatures, taking stress off the heating system.
Other institutions applying this technology found that it paid for itself within three to five years, Mayfield’s preliminary research showed.
“Some universities that have started using geo-thermal heat pumps are saving literally hundreds of thousands of dollars a year in heating and cooling costs,” she says. Given that the majority of Emory’s buildings are heated and cooled through centralized steam and chilled water distribution, it is unclear if Emory would realize similar savings, but Mayfield recommends investigating the technology — particularly for buildings not on the central system.
Anaerobic digesters and
“Emory currently uses natural gas to power its steam plant, and we looked at the possibility of displacing some of that gas with a more renewable fuel,” Mayfield says. By putting campus food waste, grass clippings and woody debris into an anaerobic digester — a high-tech composting system — Emory could turn this waste into its own supply of methane gas.
“In addition to providing a renewable energy source in the methane, it could reduce the waste that Emory sends to a landfill every year,” Mayfield says. Again, costs will be a major factor in determining whether this technology is feasible at Emory.
Mayfield’s research was part of an ongoing effort by the Office of Sustainability Initiatives to determine the feasibility of using carbon offsets to help fund renewable energy on campus and as one more way to help Emory shrink its carbon footprint.
“The key to success is willing and supportive people who want to find ways to make renewable energy work,” Mayfield says. “Emory has an advantage in that the leadership, from the president on down, is firmly committed to sustainability.”
Mayfield completed her term as sustainability scholar-in-residence this month and is currently executive director of the Western North Carolina Alliance, an environmental advocacy group based in Asheville.