When Cornell's energy supplier, NYSEG, made an Aug. 8 request for a voluntary power reduction – to help avoid rolling blackouts during a midsummer heat wave in Tompkins County and New York state – members of the campus community responded immediately.

The energy savings from hundreds of switched-off lights, office machines, coffee makers and other electrical devices added to the significant power-usage reduction from Lake Source Cooling, the innovative, year-old system that air conditions campus buildings from the perennially chilly waters in Cayuga Lake.

"Within minutes of being contacted by NYSEG yesterday, we issued a campus emergency alert requesting voluntary reductions in power use by our campus community," said Stephen E. Little, the university's manager of electric procurement and energy distribution in the department of utilities. "Cornell's community has reduced its campus load by over 1,000 kilowatts, enough for approximately 1,000 homes, and is happy to do its part and help avoid possible brownouts or blackouts for our off-campus neighbors. We were already conserving enormously, compared with last year, thanks to the energy savings from Lake Source Cooling."

Since Lake Source Cooling went into operation a year ago last summer, the university has recorded an 86 percent reduction in energy used for central air conditioning and other cooling processes, according to Lanny Joyce, manager of engineering, planning and energy management. On hot days such as those experienced by upstate New Yorkers this summer, Cornell has reduced its electric power consumption by 5 to 6 megawatts – compared with pre-Lake Source Cooling days – making that much electric power available elsewhere in the county and state.

Lake Source Cooling, which provides chilled water to reduce temperatures in rooms and equipment in about half the buildings on the Cornell campus as well as at Ithaca High School facilities, does use some electric power. But the pumps that draw cold water from the depths of Cayuga Lake to a lakeside heat-transfer facility, and other pumps that circulate separate chilled water through a closed loop to the campus and back to the heat-transfer facility, use much less energy than the CFC-based refrigeration system it replaced. Details of Cornell's Lake Source Cooling system can be found at the web site http://www.utilities.cornell.edu/LSC/ .

Emergency requests for voluntary power reductions are issued once or twice a year to the campus community at the request of NYSEG. While the voluntary power reductions have the potential to reduce Cornell electric energy consumption, further reductions would affect vital research, teaching and support functions at the university, Joyce observed. He credited a student team of energy auditors who have been covering the entire campus this summer, putting up posters and "Please turn me off when you do not need me" light switch labels as part of Cornell's continuing commitment to reducing energy use.

"Most people do not realize that they should turn off their computers and computer monitors when they are not in use, saving 150 to 200 watts per machine. This can save thousands of kilowatts across the campus and local Ithaca community, " Joyce said.