Green Campuses | News

New York U Powers Up New Uber-Efficient CoGen Plant

• By Dian Schaffhauser
• 02/07/11

New York University has completed construction of an underground co-generation plant that's expected to save the university between $5 million and $8 million annually in energy costs. At the same time, the natural gas plant will decrease carbon dioxide emissions by nearly a quarter compared to its 30-year-old, oil-fired predecessor.

The new plant is located beneath a renovated public plaza in Greenwich Village, where the campus is located. The $125 million upgrade, which took 28 months to complete, provides electricity to 22 university buildings and produces heat and hot/chilled water for 37 buildings. The previous plant powered seven buildings. According to the university, the plant produces 13.4 megawatts of electricity--twice the output of the previous system.

"This CoGen plant is unique in New York and certainly around the country because of its efficiency," said John Bradley, assistant vice president for sustainability, energy, and technical services. Bradley estimated that the new co-generator plant will be "well into the 90 percent range of efficiency, where a typical boiler plant is 50 [percent] to 60 percent efficient."

A document on the university's Web site explained how the new co-generation plant works. The plant runs on compressed natural gas, which powers two gas turbines whose rotation generates 11 megawatts of electricity. Hot waste exhaust from the process is directed to recovery generators, which produce steam. Once steam is created, it's piped to a steam turbine electrical generator, which produces an additional 2.4 megawatts of electricity. After the steam has passed through that turbine, it's used to heat water for the campus in two heat exchangers and to run a turbine-driven chiller that produces 2,000 tons of chilled water.

In 2007 New York U President John Sexton signed the American College & University Presidents Climate Commitment. This committed the university to creating a climate action plan, which was published in March 2010, and setting a target date--2040--for reaching carbon neutrality. As part of the plan, the institution completed a greenhouse gas inventory, which calculated that 96.5 percent of its gas emissions were tied to its energy system used to heat, cool, and power university buildings.

Prior to the energy plant upgrade, the university had managed to cut energy emissions by 20 percent to 25 percent through other means. The new plant is projected to reduce emissions by another 20 percent.

The plant exists beneath a new "green" urban plaza that's open to the public and combines roofed areas with decks, benches, trees, and native plants.