Cornell Sees Savings in Lake Source Cooling

Cornell Sees Savings in Lake Source Cooling

A controversial $60 million project could help Cornell University spend about 20 million fewer kilowatt-hours of electric energy per year than it used to for cooling, and help reduce the burning of coal in power plants by about 25 million pounds a year.

Cornell officials say the university’s Lake Source Cooling system, proposed in 1994 and launched in July, is helping them project big savings and environmental benefits. The system uses cold water from the depths of Cayuga Lake to replace conventional refrigeration to cool campus buildings and equipment.

Environmentalists had feared that the project’s heat-exchange system would disrupt Cayuga Lake’s ecosystem, and exacerbate the 722-square-mile water basin’s pollution problems. Cornell maintains that the project, one of the largest environmental engineering projects undertaken by a university, is of no harm to the lake and its residents.

Taking the Plunge

Although the concept of using naturally cold, deep water for a cooling system is not new, this is the first such installation by a university anywhere in the world and the first to be deployed in a small freshwater lake. Cayuga Lake, part of the chain of Finger Lakes with unique glacial origins and striking geologic features, is the longest and second-deepest of the Finger Lakes.

William "Lanny" Joyce, Cornell utilities engineer and director of the LSC project, stands behind his team’s efforts:

"We have built something that will last 75 to 100 years, whereas conventional chillers last about 30 years. It's a much more passive system with fewer moving parts," Joyce said.

Cornell’s old cooling system consisted of eight "chillers," essentially massive water coolers, in which a refrigerant is alternately compressed and expanded to transfer heat out of water that is circulated to cooling systems in campus buildings.

The new system helped the university keep up with campus growth, combat rising energy costs, replace aging equipment, and eliminate ozone-depleting chlorofluorocarbon refrigerants, Joyce said.

"We are saving in that all we have are water pumps," Joyce said.

“The cost of building the LSC system was more than 50% higher than the cost of a new refrigeration plant, the long-term savings were attractive, and the environmental benefits offered a bonus,” Joyce said.

Project spin-offs include a new town park at the north end of the marina adjacent to the plant, and new sidewalks, creating a continuous pedestrian link running 2 1/2 miles from campus to the Tompkins County Chamber of Commerce office on East Shore Drive.

A comparable system is in operation to cool downtown businesses in Stockholm, Sweden, dissipating heat into the Baltic Sea, and an experimental system cools the Natural Energy Laboratory of Hawaii. Systems are under consideration for downtown Toronto and a research facility near Rochester, both drawing from Lake Ontario.

Environmental Worries

According to a related report published in the Ithaca Journal, environmentalists and area residents fear for the lake’s health in general. Reports cite contamination from phosphorus from wastewater treatment plants; coliform and sediment levels from erosion; and development around the lake.

Still, Cornell says its LSC system is no cause for alarm. As water with relatively low phosphorus levels will be discharged into an area with high phosphorus values, heat-exchange water -- which is not a new source of phosphorus as it comes from within the lake -- will dilute the phosphorus in the area, Robert R. Bland, director of Cornell's Environmental Compliance Office, told a reporter.

Bland added that Cornell will continue monitoring, and, if Lake Source Cooling is found to harm the lake in any way, steps will be taken to reverse the problem.



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