System Relies on Ice to Chill Buildings

Graphic shows how ice is used to cool office buildings; 2c x 3 1/2 inches; 96.3 mm x 88.9 mm (Chris Kaeser - AP)

Coulard, an expert in energy efficiency, was hired by the company four years ago to develop the energy services department.

"I've been doing green since before it was cool," he said. "The idea of not only saving money for large companies, but doing something that benefits the environment is win-win. It's doing the right thing."

Engineers say the power-saving results from the system are impressive. And it translates into millions of dollars saved in energy bills for the companies.

Ice storage at Credit Suisse lowers the facility's peak energy use by 900 kilowatts, and reduces overall electric usage by 2.15 million kilowatt-hours annually _ enough to power about 200 homes.

At the Morgan Stanley facility in Westchester County, the system reduces peak energy use by 740 kilowatts and overall electricity usage by 900,000 kilowatt hours annually.

Both companies received incentives from the New York State Energy Research and Development Authority under a program designed to improve the power grid and help businesses reduce operating costs.

The technology isn't for every office space. There has to be room to install the large tanks. And costs are considerable: Credit Suisse spent more than $3 million to renovate its cooling system; and Morgan Stanley's costs were comparable, which means the technology is best suited to large companies.

"This is for companies that want to go green but that there has to be other benefits, returns on investments," Coulard said. "It works for larger companies because their cooling costs are so considerable."