Lake Source Cooling
Lake Source Cooling is one of the most significant environmental initiatives ever undertaken by an American university to promote a sustainable future. With its startup in July 2000, Lake Source Cooling (LSC) upgraded the central campus chilled water system to a more environmentally sound design that conserves energy and utilizes a renewable resource, the deep cold waters of nearby Cayuga Lake. With a price tag of $58.5 million, a higher cost than simply replacing the existing chillers with new, LSC was a significant project. However, it provides the university with a method of cooling that eliminates refrigeration equipment and its associated energy use, impacts on the environment from energy use, and any future problems with the new generation of refrigerants that have been designed to replace CFC's.
The renewable resource tapped by LSC has reduced Cornell's reliance on fossil fuels. LSC saves over 20 million kWh per year versus previous cooling methods, enough to continuously supply 2,500 homes in Tompkins County! This represents about an 85% reduction in energy use for campus cooling. Energy savings for an average year is depicted by the following chart:
A well proven cooling technology transfers the heat from the campus chilled water to the lake water through heat exchangers that separate the lake water and campus water- the two loops never mix. Because heat flows naturally from hot to cold, no extra energy is required beyond that needed to move the water through pipes.
Six of the university's old refrigeration machines, known as chillers, utilized CFC refrigerants. CFC's have been determined to be associated with ozone depletion in the upper atmosphere of the earth, and have been banned from production or importation in the United States. In order to provide reliable cooling into the next century, the university along with all other building owners must replace all equipment that utilizes these outdated refrigerants.
LSC is a long term solution to the university's cooling needs. LSC is designed to last 75 to 100 years, over twice the typical life of chillers. LSC is cost effective in the long run due to its energy savings, long life, replacement of current chillers that are outdated due to their use of CFC's, and because together with remaining non-CFC chillers and the Thermal Storage Tank, it will allow the university to meet cooling needs for many years to come.
LSC was proposed in 1994 and approved by the New York State Department of Environmental Conservation in 1998. Nearly four years of environmental study and review resulted in a four volume, 1500 page Environmental Impact Statement that thoroughly described the potential impacts of the project on the lake. The DEC determined that LSC could provide the stated environmental benefits without harm to Cayuga Lake. Even so, the DEC has required Cornell to include many special features in the construction and operation of the project to further minimize any impacts identified. In addition, they required the university to carry out a lake monitoring program that, through data and independent oversight, will verify its safe operation on the lake.
Construction began in March of 1999, and the project was completed in the year 2000. The construction phase provided many benefits to the public, which total over $2 million in value to the taxpayers of the City and Town of Ithaca and the City of Ithaca School District. Participants in the project include Cornell University, the City of Ithaca, the City of Ithaca School District, and the Town of Ithaca.