Using Seawater to Slash Energy Bills 20%

Bill Mahlum
Bill Mahlum

HONOLULU (KHNL) -- Building owners in downtown Honolulu could soon save more than 20% on their air conditioning bill every year, thanks to an upcoming project that aims to make our islands less dependent on oil.

On Monday, Honolulu Seawater Air Conditioning announced it has secured $10 million in equity funding needed to launch the environmentally-friendly project.

The project involves using seawater to run air conditioners. The high-tech system will be set up in Kakaako, which will pump water from the ocean about four miles offshore, 1600 feet deep.

A green and clean way to cool buildings in downtown Honolulu is on the horizon.

"Oh, it's great for Hawaii because first of all, you need to be energy independent here and this is a good step forward. We avoid 16 megawatts of electric use just by hooking up our system," said Bill Mahlum, President of Honolulu Seawater Air Conditioning.

Here's how it works: a pump brings cold seawater to a cooling station onshore. Heat exchangers transfer the seawater's cold temperature to freshwater. That chilled freshwater then circulates through building AC's. The seawater and freshwater never mix. The now warm seawater is pumped back to the ocean.

Mahlum says hooking up to this system is cheaper than manufacturing air conditioning on site.

"We're very stable in our price. We have a flat price range. It goes up not with inflation, no more than half of inflation over the next 25 years whereas now, everyone's victimized by the oil crisis in the world," said Mahlum.

Construction starts January of next year. The zero-emissions system should be up and running by June of 2010.

Mahlum says Hawaiian Electric Company can avoid a whole year of expansion once this system is in place.

Targetted customers include The Queen's Hospital, Bishop Square, and the Federal Courthouse.

A system serving buildings in Waikiki is also in the works.