Honolulu to use sea water to cool buildings

The amount of energy it takes to cool buildings citywide is enormous, and such energy is usually obtained by burning up some precious resource. Honolulu Seawater Air Conditioning (HSWAC) is set to change that as it is now going to cool down buildings with seawater, rather than using fossil fuel-based air conditioning units. Private investors have put up nearly $11 M, completing the funding effort for the $152 M project, with about half of the final funding coming from investors from Honolulu. The system will pump cool water, about 45° F, from 1,600 feet below the ocean waves. The water will travel through the pump system to an onshore station where it will cool fresh water that circulates in a closed loop through customers’ buildings in downtown Honolulu. Once the cold seawater has done its job, it is pumped back into the ocean at a shallower level, going through a diffuser to ensure proper mixing and dilution to the surrounding sea. Renewable Energy Innovations, LLC, pioneered the system in Sweden and have shown that it works quite well.

Honolulu depends on imported oil and fossil fuels for 90% of its electricity, so to use seawater instead would drop costs by over 20%. Construction on the project is set to start the first week of January, 2009.
Via