It's 12:45 p.m. on a Thursday afternoon, and W.S. (Lanny) Joyce, a manager in the Utilities and Energy Management department at Cornell, is teaching a class on conservation. Call it, maybe, Saving Energy at Cornell 101.

Joyce is proud of the university staff's accomplishments in reducing energy use and associated environmental impacts. And although a single class (it's really Science and Technology Studies 429) is not nearly enough to tell the story of Cornell's ongoing conservation efforts, it is a start. So Joyce, Eng. '81, sets up his PowerPoint and rewinds to the end of the 19th century.

Cornell has a long tradition of making energy history – starting back in the 1880s, when an innovative water-powered dynamo was built in Fall Creek gorge to light campus buildings. Campus growth and a need for heat led to three district heating plants, which operated until they were replaced with the current central heating plant (CHP) in 1922.

The CHP began with four boilers, designed to produce steam from Pennsylvania anthracite coal. The facility has required expansions over the years, and the boilers, fuels and power generation have changed – but the CHP remains at the core of campus heat and electricity production. The plant relies on coal as a primary fuel, supplemented with either natural gas or oil when needed. The operations and maintenance staff at the plant assure a reliable steam supply to campus via computer control systems that automatically react to a need for heat. Filters and strict fuel specifications minimize emissions from the two 225-foot brick chimneys.

Cornell buys about 85 percent of its electricity from New York State Electric and Gas (NYSEG). Of the remaining 15 percent, 2 percent comes from the hydroelectric power generated from water wending its way down the hill from Beebe Lake to turbines in the hydroplant under the suspension bridge. The other 13 percent is a product of cogeneration.

And now, one of Joyce's favorite topics. Cogeneration, or cogen, is based on a principle that's both simple and creative. Cogeneration produces heat and electricity from one fuel. In a conventional power plant, a boiler produces high-pressure steam that is used to drive a turbine, which in turn drives an alternator to produce electricity. The exhaust steam is generally condensed to water, which goes back to the boiler and the heat released in condensation is wasted. Cornell's cogeneration plant, built in 1986, heats buildings via an underground steam supply system consisting of 13 miles of piping. It is then reheated and sent out again as steam. Before the steam is sent to the campus, it is passed through two steam turbines to produce electricity.

Normal generating plant efficiency is 35 to 50 percent. With the Cornell cogen system, efficiency is boosted to 80 percent. And that means savings in both money and resources. "It's a really wonderful technology," says Joyce, "cost-effectively increasing efficiency and helping reduce environmental impacts."

From heating to cooling now – specifically, to one of the largest successes in reducing energy use and overall environmental impact: Lake Source Cooling (LSC).

LSC was conceived in 1994. Like cogen, it is a simple concept; in this case drawing cool water from 250 feet beneath the surface of Cayuga Lake to the LSC plant on Lake Shore Drive, where heat energy is added from the separate campus closed system, then returning the water to the lake. The cooled campus water is then circulated through the campus to remove heat from the buildings.

The $58 million project was completed in 2000. The result: Cornell now uses 86 percent less energy for cooling – and no longer relies on harmful chlorofluorocarbon-based refrigerants. Cayuga Lake continues to be carefully studied and monitored, but no negative ecological effects have been found.

Joyce ticks off other campuswide Energy Conservation Initiative efforts: the recently completed $1.9 million energy efficiency project in the Biotechnology Building; an $850,000 project that has 1 million square feet newly fitted with more efficient lighting; the variable speed drives that allow systems to run only at the required levels; and the updated direct digital controls that make systems more responsive and easily monitored.

Anyone can now access campus energy use in nearly any building via the department's Web site, he adds. And the university also has received nearly $1 million in rebates from the New York State Energy Research and Development Authority for implementing energy-efficient practices.

The class is winding down, and Joyce offers a final thought.

Take responsibility for energy conservation on an individual level, he tells the class. Turn off things you're not using, close fume hoods and shut down computers at night. "The university has yet to turn down an energy conservation program that makes good economic sense," he says. "We'll do everything we can that's cost effective to reduce energy usage. Period."