By the end of the year, two new gas turbine generators will power up at Cornell University. They are expected to improve the campus' energy efficiency, lower emissions and make the campus self-sufficient if the local electricity source fails.

Five years of planning and two years of construction on the Cornell Combined Heat and Power addition to the central heating plant on campus are winding down. Using natural gas, the two new generators will allow the Cornell power plant to provide for all steam needs on campus and about 80 percent of the electricity normally required.

"We'll be doing more of the whole piece (of Cornell's energy needs) at 75 percent efficiency," said Edward Wilson, manager of Cornell's central heating plant.

Though people on campus won't notice a difference during their daily routine once the generators power up, the change is expected to have an impact for those keeping track of Cornell's carbon footprint.

Once the CCHP is in full use, it "will reduce our carbon footprint by 20 percent right off the bat," said Dan Roth, sustainability coordinator in the Office of Environmental Compliance and Sustainability.

Plans for the CCHP predate President David Skorton's signing the American College and University Presidents Climate Commitment in 2006 and the release of Cornell's Climate Action Plan in September. The Climate Action Plan includes the administration's goal of making the campus climate neutral by 2050.

Wilson said the new combined heat and power generators will achieve up to 75 percent efficiency, compared to about 49 percent for producing the same amount of heat and electricity through separate processes. By creating steam and electricity through the same process rather than separately, the new system will produce the same amount with much less fuel consumption.

Wilson said the plant's total coal consumption will be cut nearly by half when the natural gas-powered generators come online. Energy usually lost in the conversion process from fuel to heat and electricity will be harnessed and fed back into the system by taking steam generated in the waste heat boiler, using it to produce more electrical power in a steam turbine generator, and then sending it to campus for space heating and other thermal requirements.

The project was first conceived in 2002, Wilson said, when energy growth on campus was projected to outstrip the existing facility's capacity. Additional reasons for the project outlined on Cornell's Web site include a need to update the campus power facility, add fuel flexibility to the campus' energy portfolio, control cost and environmental emissions, and achieve campus sustainability goals.

If the electric grid in Ithaca were to fail, the CCHP would enable Cornell to sustain its own electricity and steam consumption indefinitely.

"Cornell would be in a position to help the local community," Wilson said.

In addition, the new plant office, which will include showers for employees and a conference room and will be completed after the CCHP is up and running, is expected to earn a LEED silver rating for its under-slab hydronic thermal storage system and hot water via roof- mounted solar panels. About half of the building's energy will be provided through the solar panels.