Thursday, September 04, 2008

Belvoir taps into geothermal energy

Geothermal heating and cooling systems are popular for their “down to Earth” method of using renewable energy not ordinarily found in other systems. Literally.

That’s why military installations, including Fort Belvoir, are strongly considering this alternative as a priority for future energy conservation.
Bob Zinkwich, an energy engineer at Belvoir’s Directorate of Public Works, said ground-source heat pumps have taken the reins as the number one energy source for the Army. They use the relatively constant temperature of the ground to provide heating and cooling to various types of buildings, including residential and commercial.

As Zinkwich explains, the systems exchange heat with the Earth using a network of fluid-filled, high-density polyethylene pipes. In the winter, the fluid within the pipes extracts heat from the Earth and carries it into a building. In the summer, heat from the building is carried through the pipes and deposited back into the Earth. The network of pipes also takes the place of a conventional cooling tower and boiler.
At Belvoir, three buildings use this method already - the veterinary clinic, visitor’s center and airfield operations center at Davison Army Airfield.

Judging by its low operating cost, as well as its ability to deliver four units of energy for every one unit of electrical energy used, Zinkwich believes many more are on the horizon. 

“The Army is adamant about achieving renewable energy goals and ground source heat pumps are considered the first choice with any new construction,” he said. “At Fort Meade, 23 systems have already been installed there. Fort McNair and A.P. Hill have also followed suit, with 64 and 29 systems, respectively.

“In the long run, it’s hands-down the best at providing a savings and is environmentally friendly because it emits no carbon dioxide, carbon monoxide or other greenhouse gasses,” Zinkwich said. 

In what has become a familiar trend in energy conservation, Zinkwich acknowledges that GSHP systems are initially costly to install. Presently, a residential GSHP system could range between $10,000 and $12,000 for a homeowner.

However, unlike air conditioners and standard heat pumps, geothermal units are more reliable and require less maintenance because they’re installed indoors and are not subject to rain, snow, ice and extreme temperature.

Without any need to burn natural gas, propane or fuel oil, the impact of skyrocketing fuel costs will not be as severe for homeowners, either, Zinkwich said. Statistically, the initial cost of installing a geothermal system can be recovered within three to five years.