Reducing gas emissions more than hot air at Princeton

Princeton NJ -- The University has achieved a substantial reduction over the last decade in its greenhouse gas emissions, putting it ahead of a statewide plan to reduce air pollution by colleges and universities.

Compared to 1990 levels, the University has cut by 4.5 percent the amount of greenhouse gases that it either releases directly into the atmosphere or is responsible for releasing because of its consumption of energy made by utility companies.

Princeton joined last year with the other 55 colleges and universities in New Jersey in pledging to reduce the emission of greenhouse gases by 3.5 percent from 1990 levels.

The bulk of the reduction at Princeton is the result of its cogeneration plant, which began operating in 1996 and provides both steam and electricity to the campus. Before building the plant, Princeton burned natural gas and oil to fire boilers that make steam. The steam heats nearly all the campus buildings and, in the summer, runs machines that chill water for air conditioning.

The cogeneration plant burns natural gas and a cleaner grade of oil to make steam as well as nearly all the electricity used on campus. The fuel runs a jet engine almost identical to those used in some military airplanes. The thrust from the engine drives an electrical generator, while the hot exhaust boils water for steam.

"We are making the same end products with less fuel, so in the end we are polluting the environment less," said Ted Borer, manager of mechanical systems in the facilities department.

The system also saves the University considerably on its electric bill. Assuming that the cost of making steam remained the same, the University is able to make electricity for an added fuel and maintenance cost of just 4 cents per kilowatt-hour, or about half of what it would be charged by public utilities.

To keep track of the efficiencies, Borer led the development of a worksheet that is now being used by the New Jersey Higher Education Partnership for Sustainability, an alliance that is spearheading the greenhouse gas reduction effort on New Jersey campuses. The worksheet allows campus facility engineers to plug in the different fuels they burn and the amount of electricity they buy and calculate the corresponding amount of carbon dioxide emissions.

According to Borer's worksheet, Princeton was responsible for 121,000 tons of carbon dioxide emissions in 1990 and 115,500 tons in 2000. The reduction is even more remarkable considering that the square footage of heated and cooled space grew by nearly 10 percent and the campus population grew by 3 percent.

Borer noted, however, that the bottom line is the actual reduction in greenhouse gas emissions, not the reduction per square foot. "The planet doesn't care how much you grew; it only cares how much pollution you dumped into the ecosystem."

To match the improvements over the next decade will be "tremendously difficult," Borer said. "There is still some opportunity there though, and we can go after it."

 
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March 11, 2002
Vol. 91, No. 19
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Contents

In the news
• 'Green' initiatives a go for facilities department
• Climate change top concern for 21st century
• Reducing gas emissions more than hot air at Princeton
• Tilghman co-chairs state initiative
• Camera lens was Lewis Carroll's looking glass

People
• Marsh appointed associate provost
• Faculty/staff reservists committed to two careers
• Baker to speak at Class Day
• Briefs
• Spotlight

Sections
• By the numbers: Student publications
• Nassau Notes
• Calendar of events 

Editor: Ruth Stevens
Calendar editor: Carolyn Geller
Staff writers: Jennifer Greenstein Altmann, Steven Schultz
Contributing writers: Marilyn Marks, Evelyn Tu
Photographer: Denise Applewhite
Design: Mahlon Lovett, Laurel Masten Cantor
Web edition: Mahlon Lovett