[ OUR OPINION ]
Testing the waters for
energy conservation
and productionWHILE Hawaii's ocean environment presents some unique disadvantages when it comes to commerce and travel, two recent ventures are capitalizing on the surrounding sea. If successful, both enterprises could usher in novel methods for energy conservation and production. They point the way toward the state's development of technological advances that make use of what we have instead of importing resources we lack.
THE ISSUE
Two projects hope to use the ocean's temperature and power in innovative ways.The University of Hawaii and the Honolulu Board of Water Supply are looking into "district cooling," a process that uses cold water as a chilling agent for air-conditioning systems at UH's medical school in Kakaako. Conventional air conditioners use electrically powered compressors to circulate air cooled by refrigerant gas. Cold sea water can power a system and/or cool buildings directly, conserving fresh water as well as fuel needed for producing electricity.
The water board has approved a $1.6 million study to examine whether district cooling is feasible at the medical school and hopes the method can be expanded for other facilities planned in the Kakaako development district.
A similar process is already in use at the Natural Energy Laboratory of Hawaii at Keahole on the Big Island. Cold water pumped from deep in the ocean directly cools administration and lab buildings with a total of 67,200 cubic feet. The system saves NELHA nearly $4,000 a month in electricity costs and requires much less maintenance than compressor systems.
BWS should consult with NELHA as well as review a state study completed in 1994 that evaluated a deep-water-source cooling system for possible use at West Beach, now known as the Ko Olina area. The study concluded that an ocean-based, deep-water system was technically and economically feasible when compared to conventional networks.
Clifford Jamile, the board's chief engineer, acknowledges that analysis of the cost of the project, now estimated at between $3.5 million and $6 million, as well as environmental concerns will be necessary. Drawing and returning large amounts of water from the ocean may have harmful affects on marine biology and there may be limits if withdrawal exceeds natural renewal. However, because there could be significant savings in energy and operating costs, and reduction of pollutants and releases of environmentally harmful refrigerant gases, the project deserves full consideration.
Jamile says using Hawaii's oceans for more than recreation is an idea whose time has come and apparently the Navy agrees. The Navy is experimenting with harnessing the power of waves to produce electricity, using a subsurface buoy that moves up and down with ocean swells. The movement drives an electrical generator to which it is attached and will eventually send power ashore through an underwater cable.
The device is expected to yield an average of 20 kilowatts, up to a peak of 50 kilowatts, that will be used to power between five and eight homes at the Marine Corps Base in Kaneohe. The buoy is being developed by Ocean Power Technologies Inc., a New Jersey company that already has tested several prototypes successfully.
Visual effects seem minimal with only the buoy's mast and navigational warnings above surface. However, like the BWS project, environmental assessments -- how the buoys may affect fishing, marine wildlife and ocean recreation -- will have to be conducted as the Navy proceeds with possible expansion.
