[EAS] Cold Water Energy

Peter J. Kindlmann pjk at design.eng.yale.edu
Fri Jun 10 02:38:31 EDT 2005

(from INNOVATION, 8 June 2005)

       With supplies of fossil fuel now declining, John Piña Craven, former
chief scientist for the Navy's Special Projects Office, has developed a
plan to use cold water pumped up from the depths of the ocean to provide
low-cost and environmentally sustainable power, water and food to a new
development in the Marianas. The proposal has already won $75 million from
a Memphis, Tennessee, venture capital firm, and $1.5 million in federal
funding. The cold-water energy system exploits the difference in
temperatures between deep-sea water -- below 3,000 feet -- and surface
water and air. A pipe pulls up the frigid water -- 39 degrees F -- to the
surface, where it's run through heat exchangers to produce unlimited air
conditioning that costs almost nothing. Condensation is gathered to provide
freshwater for drinking and irrigation, and by directing some of the flow
through a contraption Craven calls a hurricane tower, electricity is
generated as well. Once proven, Craven plans to use his energy system to
nurture a small experimental Hawaiian vineyard and pineapple farm, where he
says cold-water irrigation enables him to produce three crop cycles a year
rather than one or two. In the Marianas, the system will provide water and
energy for 100 townhouses, a golf course, soccer fields and an athletic
complex aimed at Japanese tourists. It will also sell freshwater to hotels
now relying on desalination plants. "The oceans are the biggest solar
collector on Earth, and there's enough energy in them to supply a thousand
times the world's needs. If you want to depend on nature, the oceans are
the only energy source big enough to tap," says a senior scientist at the
National Oceanic and Atmospheric Administration (NOAA). (Wired.com June 2005)

Remember my mailing "Is it Original"? 
Well, this idea of energy recovery from deep 
ocean water temperature differentials is coming 
around again. In the '70s I recall talks by 
Clarence Zener (of the Zener diode) advocating 
this form of energy recovery. There are patents 
from that period, e.g. 
which mentions other patents by Zener and others. 
There are also interesting technical challenges 
with such energy recovery, such as having to deal 
with two-phase mixtures. (See the cited patent.)

The other poignant thing about this item is that 
it should be proposed for the Marianas. To quote 
from a recent PBS NOW program 
"The Marianas are a Commonwealth of the United 
States. Technically that means they're part of 
America. Clothing manufactured here even bears 
the label "Made in the USA." But here's the 
thing: many U.S. labor laws don't apply here. 
Back in the 1970's, Marianas officials negotiated 
with Congress to make sure of that. These 
factories depend on a steady stream of workers 
recruited from third world countries. Some of 
them net as little as $350 a year."

The working conditions are as bad, sometimes 
possibly worse, than those in the New York 
garment industry sweatshops prior to the 1911 
Triangle Shirt Factory fire 
Read the rest of the PBS transcript, it's rather 
dismal and involves some very prominent 
Washington politicians and lobbyists. I don't 
think those Marianas garment workers are going to 
benefit from this energy proposal. Technically 
and socially, the proposal is mostly froth, like 
a lot of technology proposals these days.  --PJK

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