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. Last Updated: 07/27/2016

U.S. University Uses Lake to Cool Off




ITHACA, New York -- On humid days, frigid water piped from the depths of Cayuga Lake keeps everyone cool in the dormitories, classrooms and research laboratories at Cornell University.


Because there's nothing quite like it anywhere in the world, the school's new lake-chilled, air-conditioning system could someday be a model copied in communities that lie next to oceans or deep inland waters such as the Great Lakes.


"We're going to a point where the water's consistently cold. Nobody's gone this deep in a lake before,'' said engineer Lanny Joyce, who resurrected an old idea championed by Cornell as an environmental boon but scorned by Ralph Nader as "an ill-advised boondoggle.''


The ecological impact of "lake source cooling'' may not be known for weeks at the earliest, but environmentalists have been feuding for the greenest high ground since the project began coursing over regulatory hurdles six years ago.


At 127.5 meters, Cayuga is the second deepest of the 11 fjordlike Finger Lakes in west-central New York f long, slender exclamation marks gouged by glaciers during the Ice Age.


In July, a pipeline strung 3 kilometers north along the lake bed to a depth of 75 meters began pumping 3.8-degree-Celsius water to a heat-transfer station near Ithaca. Water that far down hardly varies in temperature all year long.


The piped lake water, flowing past heat-exchanging steel plates, absorbs the mugginess in the 1.1-million-square-meter Ivy League campus. Never mixing with chemically tainted water in Cornell's central air-conditioning circuit it is then returned 6 degrees to 9 degrees hotter in the lake's warm, shallow south end.


The $60 million project will cut the school's $1.5 million annual electricity bill for air conditioning by 80 percent. It will likely pay for itself in a generation. And it should last 75 to 100 years, twice as long as conventional refrigerators.


The switch also trims Cornell's reliance on coal-burning power plants and dispenses with chlorofluorocarbons f chemicals in traditional refrigerants blamed for thinning the ozone layer.


But at what cost to the lake?


A tenacious band of residents worries that the nutrient-rich discharge into 2.7 meters of water will create noxious blooms of algae in a lake basin already dirtied by decades of human interaction.


"It's like pouring gasoline on a fire,'' said Alex Horne, an ecological engineering professor at the University of California at Berkeley who was hired by the Cayuga Lake Defense Fund to evaluate the project. "I don't think Cornell can well enough prove they're not going to cause a nuisance.''


Cornell scientists counter that water sucked up from the depths at a maximum summertime rate of 174 million liters a day may actually improve the 61-kilometer-long lake's turbid southern tip.


"Algae will bloom in that water moved from the bottom but the concentration of algae will be lower than the surface water that's being displaced,'' said Nelson Hairston, an ecology professor at Cornell who chaired the project's scientific review committee.


Hairston added that two nearby sewage-treatment plants send 45 million liters of treated water into the lake daily "and there aren't massive algal blooms.''


The local chairman of the Sierra Club environmental group, John Kaminsky, thinks the pipeline will have no discernible effect on lake conditions. He thinks the community would do better to focus on unchecked pollutants from "nonpoint sources'' like lawns creeks and storm runoff.


But widespread praise for the project's environmental benefits has been accompanied by a drumbeat of complaints. Drawing support from Nader, the Green Party presidential nominee, critics say the permit is illegal and could weaken the federal Clean Water Act.


"Federal law says you can't issue a discharge permit that will cause or contribute to an existing water-quality violation and all 2,000 hectares of the lake's southern end is impaired,'' said Walter Hang, who runs a business here that maps toxic sites around New York.


After obtaining 17 permits from local and state agencies, the project was scrutinized by the Environmental Protection Agency, which had placed the lake's south end on a list of "impaired water bodies'' in 1998. The lake, Cornell argues, falls into a special "need more data'' category not covered by federal bans on discharges.


Horne thinks Cornell would mute criticism by agreeing to an "offset.''


"This is one of the best universities in the world and it's up to them I think to go the step further,'' he said. "This is the normal pollutant trading you would think an advanced society would be doing by now.''


Another critic, recording engineer Rich DePaolo, thinks the project has drawn so much attention since it will set a precedent for not only "whether this type of technology is implemented elsewhere but how impaired water bodies are managed throughout the country.''


So-called non-contact cooling has been widely used in industry for decades but has yet to catch on as an air-conditioning alternative.


A similar system operates in Stockholm, Sweden, drawing water from the Baltic Sea, and two more are in the works on Lake Ontario f in Rochester and Toronto. An ocean-water lab in Hawaii that draws water from 660 meters also uses some of the excess energy to air-condition several buildings.


A big, upfront investment often proves a big turnoff, said Joe Van Ryzin of Makai Ocean Engineering in Hawaii, which designed the Cornell pipeline. But he thinks the technology will prove popular eventually.


"If Cornell were Wall Street investors, they probably would have never built it,'' he said. "However, they're more world and environmentally conscious than Wall Street and they have the luxury of being able to choose the high road and do the glorious thing.


"If a city is at a location where it can do that, it really is irresponsible not to.''