Honolulu Lay Claim to Being World's Coolest City With Sea Water Air Con

The US State of Hawaii is working toward installing a massive seawater air conditioning service system in Honolulu that would cut grid power consumption by 77 million kilowatt hours a year and eliminate the need to add 14 megawatts of peak capacity. Yep, sounds a bit like gobbledygook to us too but basically, this is a good thing.

It will also reduce sewage from conventional air conditioning cooling towers by 84 million gallons a year, as well as eliminating demand for 23,000 to 69,000 pounds of the chemicals employed in conventional chillers.

With SWAC (Sea Water Air Conditioning), cold sea water is pumped from hundreds of feet below the surface to a cooling station on shore. This station transfers the salt water’s coldness to fresh water circulating in a closed loop that carries it to customer buildings. The cooling station ensures that sea water and fresh water never mix. Warmed sea water is returned to the ocean through another pipe and diffuser located at a shallower depth.

SWAC is nothing new, with successful initiatives installed in Toronto, Canada where a district cooling system uses cold water from Lake Ontario, and also at Cornell University in New York which is cooled with water from Lake Cayuga. Sweden is a world leader in SWAC development with numerous developments.

The project in Honolulu has been in development for six years, and roughly 80 percent of the design is complete. It will cost $245 million in total and is on schedule for a 2010 finish.