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dam-l Sea water irrigates crops, cools bldgs./LS



An interesting pilot in Hawaii.

Sea Water Irrigates Crops, Cools Buildings

                           KEAHOLE POINT, Hawaii, August 13, 1999 (ENS) - A
unique form of renewable energy is being used in
                           Hawaii to irrigate crops. Cold salt water from
the depths of the Pacific Ocean is being pumped into a field at the
                           Natural Energy Laboratory of Hawaii on the Big
Island to provide the plants with water.

                           The water never touches the soil or the plants
directly, but the cold pipes create condensation that waters the garden
                           and eliminates the need for conventional irrigation.

                           Chilling the roots also makes the plants perform
as they would in a perpetual spring, allowing artichokes, brussels
                           sprouts, roses and other non-tropical plant
varieties to bloom in the tropics.

                           The method is "a breakthrough for world
agriculture," says Dr. John Craven, president of Common Heritage
                           Corporation of Oahu which developed the
technique. "It allows us to convert the desert into a sustainable habitat,"
                           said Dr. Craven, holder of a degree in ocean
engineering.

                                               Dr. John Craven (Photo
courtesy CHC)

                                               The Common Heritage
Corporation (CHC) was established in 1990 by Dr.
                                               Craven to develop
environmentally sustainable ocean resources. The for-profit
                                               Hawaiian firm aims to
establish self-sufficient environmentally, economically
                                               and culturally sustainable
communities in coastal zones and islands that have
                                               access to deep ocean water.
Dr. Sylvia Earle, an internationally famous
                                               oceanographer and explorer,
is a CHC board member.

                                               The Natural Energy
Laboratory of Hawaii has a site on a lava desert near
                                               Hawaii's Kona International
Airport, which pumps water from 2,000 feet deep to
                                               improve the growth of plants
and shellfish. The experimental cold ocean water
                                               garden is one of two dozen
enterprises at the state research agency.

                                               The Natural Energy
Laboratory of Hawaii (NELH) was founded in 1974 by then
                           Hawaii Governor John Burns and Dr. Craven in his
capacity as Marine Affairs Coordinator of the State. Dr. Craven
                           continued as sponsor and chairman of the Board
until 1990, when the NELH as an independent State Corporation
                           was converted into an Authority under the
Department of Business and Economic Development.

                           Pipe carries cold sea water through strawberry
                           patch. (Photo courtesy Natural Energy Laboratory
                           of Hawaii)

                           The process of cold sea water condensation
irrigation creates
                           an environment in which nutrients are pumped up the
                           plants at a great rate. "The colder the root,
the tastier the
                           vegetables," says Dr. Craven. "When you harvest,
the plant
                           doesn't die; it just keeps growing."

                           Japan is preparing to launch a commercial
spinach-growing
                           operation on Okinawa's Kume Island, providing a
                           large-scale test of the process. That project is
expected to
                           pay for itself.

                           The Natural Energy Laboratory of Hawaii was
founded to
                           generate electricity from the temperature
differential between deep ocean water and the surface. After several costly
                           prototypes were built and tested, it appears
that at the current state of technology this method of generation is too
                           expensive for practical use.

                                                                      Diver
examines pipes feeding

seawater from the ocean depths
                                                                      to
the Natural Energy Lab (Photo

courtesy NELH)

                                                                      But
the pipelines created for that project
                                                                      by
Makai Ocean Engineering of

Waimanalo are now being used for the
                                                                      deep
ocean water irrigation garden. The
                                                                      NELH
currently pumps 16,000 gallons
                                                                      of
water each minute, at 42 degrees F.

                                                                      The
Hawaii Legislature has allocated $15

million to install a 55-inch pipeline that
                                                                      will
pump from 3,000 feet down in the

ocean. It will triple the volume of water
                                                                      for
research.

                                                                      Other
uses for the cold ocean water are
                           being developed. Two of the biggest clam and
oyster producers in the U.S. use the NELH site to cultivate more
                           than 330 million shellfish larvae a year.

                           Air conditioning of buildings with cold seawater
is also being demonstrated at the Natural Energy Laboratory of
                           Hawaii. The Lab saves more than $4,000 a month
over previous costs in the cooling of its office and laboratory
                           building.

                           Analyses by Makai Ocean Engineering have
indicated that for Guam, 10,000 hotel rooms could be air conditioned
                           with cold seawater and that the capital payback
period for installing such a system would be approximately five to
                           six years.

                           Deep lake water, too, can be used to cool
buildings. Cornell University in New York is using a similar concept to
                           provide air conditioning for its campus. The
water is drawn from 270 feet beneath Cayuga Lake in a system also
                           designed by Makai Ocean Engineering.

                           © Environment News Service (ENS) 1999. All
Rights Reserved.

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      Lori Pottinger, Director, Southern Africa Program,
        and Editor, World Rivers Review
           International Rivers Network
              1847 Berkeley Way, Berkeley, California 94703, USA
                  Tel. (510) 848 1155   Fax (510) 848 1008
                        http://www.irn.org
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