Sea-Water Air Conditioning Plan for Honolulu, Hawaii Finishes Funding
by Matthew McDermott, Brooklyn, NY on 07.10.08

photo: Getty Images
Recently the state of Hawaii passed a law requiring new buildings to install solar water heater. Now investors have secured the final funding for another green initiative in the island state: Seawater air conditioning.
The project is titled, appropriately enough, Honolulu Seawater Air Conditioning, and is being funded to the tune of $10.75 million by private investors, with the balance of the estimated $152 million in project costs to be covered by US and Swedish investors.
Touting the project, HSWAC President and CEO William Mahlum said, "Seawater air conditioning will protect businesses from the skyrocketing electric rates caused by oil price increases and everybody will benefit from a cleaner environment," adding “Reducing our use of fossil fuels and preserving the environment will be a wonderful legacy that we all leave to future generations of Hawaii residents."
Cool Water Drawn from Ocean, Circulated to Cool Buildings
The way the seawater air conditioning system will work is this: Cool water is drawn from 1,600 feet down in the ocean, pumped to a station onshore where the salt water will be used to cool fresh water being circulated in a closed-loop system through customers buildings. After cooling the circulating fresh water, the seawater is returned to the ocean at a shallower depth.
Construction is scheduled to begin in early January 2009.
Though this is interesting unto itself, and could certainly reduce fossil fuels used for air conditioning in a place where 90% of its fuel is imported, if the electricity used to power the system was generated renewably, then they’d really be onto something.
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Toronto, Canada is working on this type of downtown-core building cooling system as well.
http://www.toronto.ca/environment/initiatives/cooling.htm
Cool idea, and I'm sure they've considered this, but I wonder what the impact of ocean temps will be on things that live at 1600ft.
Also, how much energy does it take to draw water up from 1600ft down in the ocean and circulate water thru the buildings?
Hmmm... at first thought this sounded good, but it also sounds potentially destructive. What with all those pipelines, it could really disrupt the ocean environment. They'd have to be really careful to not create more problems than they are solving!
Besides, I lived in Hawaii for a good long while, and never needed A/C... but then again, I wasn't in a business suit in an office either. :)
Here's what else Hawaii needs:
A big CSP plant out at the old Kalaeloa airport so we don't have to get our electricity from Diesel any more (currently 85% comes from diesel).
We also need a light rail trunk line with electric street cars to localities, since cars in the future will be expensive and scarce.
"if the electricity used to power the system was generated renewably, then they’d really be onto something."
Didn't a very recent treehugger post state that Hawaii has set a goal of 70% of energy from renewable sources by 2030? This state government may be a step ahead of us. Go Hawaii.
All new city and county buildings are required to have a LEED Silver status as well. Everything (including the bureaucracy) moves slowly here, but in a near perfect human climate with almost every conceivable renewable energy (solar, wind, geothermal, wave, swac, etc) in constant supply, it has the potential to be quite impressive and set some pretty important precedents.
This is really good news. I heard of this a while ago and I am glad they are still moving forward with this project. It would be nice to see more hotels use this technology to reduce the grid demands. They are usually near the ocean and they use a lot of air conditioning.
Well, that only took 50 years.
Sounds like a reasonable idea, if construction costs aren't too high, lots of cold seawater down deep...I do exoect to read about objections though, concerns about the seawater discharge affecting the nearby environment...DB
This is the way things should be done.
Of course, the temperature difference could be used to drive the pumps.
This process will increase the rate our oceans and lakes are warming, I think we can come up with more innovative cooling technologies. I don't want to see this technology get a lot of attention until researchers have given it an OK. Have they?
Good stuff coming from Hawaii which I surely welcome.
Yet they have all the resources to be #1 of all US states in renewable technology - but they skid around 37- 40 right now.
Typical for republican governship. more lipservice than action.
Well, action to pocket money and power in the most reckless way they actually show aplenty.
Where did that triple digit surplus go - under this leadership? This money could be used to turn this country around in a NEW YORK MINUTE!
I can't wait!