Seawater Air Conditioning (SWAC) a renewable energy alternative

The concept of Seawater Air Conditioning (SWAC) is thought to have been first conceived by the Natural Energy Laboratory of Hawaii Authority (NELHA) at its facility at Keahole Point on the Island of Hawaii in 1983. NELHA was the first location in the United Stated to successfully deploy a deep seawater pipeline to bring deep, cold seawater ashore for alternate energy research and development in 1981. The primary purpose at the time was to support the technological advancement of the Ocean Thermal Energy Conversion (OTEC) principle. It was soon realized that utilizing this cold seawater as the primary chill water resource for air conditioning would be a great advantage and cost savings measure compared to conventional air conditioning processes. A standard air conditioning process utilizes refrigerants (typically CFC's and HCFC 's) as the primary source of "cold" for space cooling applications. The SWAC process eliminates the use of refrigerants and instead utilizes cold seawater as the primary thermodynamic chilling fluid. Alternate applications of this technology utilize cold lake water or river water. Cornell University and Ithaca High School in New York utilize cold lake water from Cayuga Lake to air condition their entire campuses. The majority of the air conditioning needs of the City of Toronto, Canada today start with cold fresh water from Lake Ontario. In these cases, the process is commonly referred to as "Lake Source Cooling (LSC) or "Deep Lake Water Cooling (DWLC)". Some of the most famous buildings in Paris, France are air conditioned and climate controlled using water from the River Seine. The largest seawater application of SWAC is for air conditioning and climate control for the majority of buildings in Stockholm, Sweden. The primary benefits of SWAC are that it can offset electrical demand by 75-85% (0.7 kW/ton), reduce the reliance on fossil fuels, reduce or entirely eliminate the need for chillers and cooling towers, achieve a rapid return on capital investment (typically 6-8 years), and is easily adaptable to conventional chill water air conditioning systems; a standard that most large commercial buildings and hotels currently utilize. The basic concept starts with the construction a deep seawater or lake water intake pipeline and pumping station. Once this chilled water is pumped on shore it is passed through a heat exchanger facility to absorb some of the heat generated in the closed, freshwater loop used to air condition the buildings. The chill water resource is then returned from whence it came (ocean, lake or river) or under certain conditions, can be used again for secondary applications.