Before long, the ocean water in Hawaii could be used for more than just surfing. Several hotel owner in Waikiki are looking to use cold deep-sea water to power air conditioning. The cold water from the ocean would be pumped into a heat exchanger that would chill a closed container of fresh water. The fresh water would be used for the air conditioning and the sea water returned to the ocean. Hotels could potentially save 20% on their cooling costs.

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