Nov. 16, 2007 It took ten years, but McDonald's is finally opening its second restaurant to use energy-efficient geothermal technology for heating and cooling.

The fast-food giant is digging deep at its new location in Pensacola, Fla., drilling 55 350-foot holes to take advantage of the Earth's constant temperature. Instead of using furnaces, water heaters, and air conditioners, the restaurant will circulate water through underground loops that move heat into the building in winter and out of the building in summer.

Restaurants are among the most intense users of energy of all types of commercial buildings, according to the Geothermal Heat Pump Consortium. McDonald's says it expects the energy savings of geothermal to more than offset the higher initial cost of creating the loop system.

McDonald's will monitor the system during the first year of operation to fine-tune the system for peak efficiency and performance, saying that once the ideal specifications have been determined, "geothermal could become just as popular for the Golden Arches as their famous burgers."

It's a claim that's been made before. In 1997 McDonald's piloted the use of geothermal heat pumps at a restaurant in the Detroit suburb of Westland, Mich., posting a 20% savings in energy costs compared to similar restaurants in the chain. At the time, the Detroit Free Press reported that McDonald's planned to roll out the system chain-wide if the prototype was successful.