October 24th, William Leahy of The Institute of Sustainable Energy and David Frassinelli, Associate Vice President for Facilities Management, Fairfield University are featured speakers at the Resilient CT! Workshop & Toolkit, where they will talk about the cost benefits of co-generation plants.
CASE STUDY: FAIRFIELD UNIVERSITY
Like many institutions of higher education, Fairfield University is under pressure to deliver a state-ofthe- art learning environment for its students while controlling escalating energy costs. Fairfield, which boasts 5,000 students, is one of 28 Jesuit colleges and universities in the United States. As part of its mission to create a premier learning environment, Fairfield embarked on a program to expand its campus footprint by 25 percent while overhauling half of its facilities. As part of the initiative, Fairfield decided to investigate building its own cogeneration plant to control rapidly rising energy costs. The university invited three energy service firms to present proposals.
Carrier analyzed Fairfield’s energy consumption trends, rates and demand charges, then looked for places on campus to employ the heat load from a generator. Carrier ultimately developed a plan that entailed installation of a 4.5 megawatt natural gas turbine and a waste heat recovery boiler. The cogeneration plant delivers about 95 percent of the university’s power needs, while the waste heat generated supplies up to 66 percent of the school’s high temperature hot water heating and cooling needs. Carrier also helped the university negotiate a fixed term fuel supply plan to control operating costs. The combined heat and power (CHP) plant earned the university a $2.3 million rebate from the State of Connecticut Department of Public Utility Control.
Fairfield University’s $9.5 million combined heat and power (CHP) plant was co-developed by Carrier’s Strategic Partnerships Group and the university’s Facilities and Campus Planning staff. The CHP system was designed to generate almost the entire electrical load of the campus while at the same time meeting up to 85 percent of the campus’s thermal requirements. The selected technology for the application was a 4.5 megawatt natural gas combustion turbine. The exhaust gases from this turbine are directed through a “waste heat recovery boiler” that generates high temperature hot water (350° F) that is used for heating in the winter and, via an absorption chiller, for cooling in the summer.
According to Ward Strosser, Strategic Partnerships Group Manager for the Middletown, Connecticut office, one of the most challenging issues when engineering a cogeneration plant is what to do with the waste heat from the turbine. “The solution we provided ensured that almost all of the waste heat would be productively used in either the campus high temperature hot water heating loop or to drive the new absorption chiller.”
William J. Auger, Fairfield University’s Manager of Energy Services added, “We are currently utilizing the heat exhaust from the turbine to supply 33 to 66 percent, depending on outside temperature, of the central utility facility heat loop. This heat loop supplies our largest energy demand buildings. The CHP does all this at a much reduced air emission rate and a higher efficiency rate than our previous systems.”
As a result of substantial increases in electric utility rates since 2005 when the cogeneration project began, the utility costs for Fairfield University were projected to approach $7 million for 2008 versus $4 million just a few years ago. These increases in overall costs made the estimated savings associated with the combined heat and power plant more than $2.25 million dollars annually.
As William Auger mentioned, the project also had an excellent impact on greenhouse gas emissions for the campus. By generating on-site power via the highly efficient, correctly sized gas turbine, the university is estimated to take more than 25 million kilowatt hours of electricity off the very congested utility grid of southwestern Connecticut. The state welcomed this alleviation of strain on the electrical infrastructure, and the CHP plant qualified the university for $2.3 million in grant monies from the Department of Public Utility Control. This project is expected to reduce the university’s overall carbon footprint by more than 10,000 metric tons per year.