|
OCEAN PIONEER MINES ENERGY THAT IS COOL, CLEAN AND FREE |
KEAHOLE POINT, HAWAII -- DR. JOHN P. CRAVEN has made a living by taming a part of the planet that few people think much about and almost no one visits: the bottom of the deep blue sea.
As head of the Navy's Deep Submergence Systems Project in the 1960's, he pioneered new technologies to plumb the ocean's depths, developing the world's most advanced vehicles for deep-ocean search, rescue and salvage. He also developed an abiding faith in what he saw as the sea's untapped economic potential.
IN the 1970's he came to this promontory of ancient lava on the Big Island of Hawaii with the dream of bringing the deep ocean onto dry land, pumping cold water from the pacific's depths to study the development of new industries and life support systems for the human race. From that vision has flowed discoveries great and small.
"Oh, wow!" Dr. Craven, now 68 years old, said recently as he showed a visitor a lush garden here watered in a novel method of using seawater. "Holy smoke! Look at the size of that zucchini."
The 870 acre laboratory and commercial park that developed around his original idea has become the world leader in developing the remarkable potential of cold seawater for such disparate things as growing strawberries, air-conditioning buildings, raising lobsters and making electricity.
Pipes that are 12, 18 and 40 inches in diameter run through the breakwater here and plunge far beneath the waves to haul up deep water as cool as 45 degrees Fahrenheit, about the same as a refrigerator. Other pipes collect warm water, typically a tepid 80 degrees. The temperature difference between the two is crucial to much of the magic that goes on here.
Once on land the ocean water flows through a four-story melange of concrete and machinery that cranks out 210 kilowatts of electricity in the newest and largest generator of its kind in the world. In other parts of the laboratory cold water goes through heat exchangers to air-condition a handful of buildings, and in the near future will circulate through the nearby Keahole airport to cool it as well.
Perhaps most impressively, the cool water flows down the road in buried pipelines to nourish a host of small companies that have sprung up over the years to exploit the nutrient-rich seawater for aquaculture. The concerns are raising lobsters, a type of flounder highly prized by the Japanese for sashimi, such sea vegetables as ogo, nori and ele ele, and a kind of microalgae rich in protein known as spirulina, which is sold in a dietary supplement in health food stores.
Most recently, the cool water has been run through a welter of pipes that sustain a large vegetable garden here. The pipes cause water vapor in the humid air to condense and drip onto the soil and root systems, producing an Eden-like profusion of crops that turn out to be exceptionally large and sweet.
"All the other things that came along turn out to be more important than electricity," said Dr. Craven while munching a carrot from his seawater garden. "You bring up that cold water and you've got it made."
He recently founded the Common Heritage Corporation, based in Honolulu, to commercialize the cold-water techniques, including the emerging ones for agriculture. So far, his small research team has tested them on 79 kinds of fruits and vegetables.
"We're doing something so off the wall that most people laugh," said Kevin Sue Rohan, a tan, athletic woman in her 30's who oversees the experimental garden, often with three small children in tow. "But we're doing it successfully."
Dr. Craven sees the mix of cold water electrical production, air conditioning, aquaculture and agriculture as a boon to the developing world, much of which lies in the equatorial band of the planet where strong sunlight generates big differences between the ocean's upper and lower reaches.
"Deep ocean water is a resource that can, today, provide environmentally sustainable economic self-sufficiency and independence for tropical island and coastal nations around the world," he wrote last year in the Marine Technology Society Journal.
Dr. Thomas H. Daniel, the laboratory's chief scientist, called Dr. Craven a gifted visionary.
"He saw before many other people that the ocean is a very large potential resource," Dr. Daniel said. "We can get 10 terawatts of electricity out of the oceans continuously, which is about man's usage right now."
Dr. Craven was born in Brooklyn in the shadow of the Williamsburg Bridge and joined the Navy during World War II, serving in Hawaii and earning two battle stars before being sent to Cornell University for advanced education. After the war, under the G.I. Bill, he studied at the California Institute of Technology and the University of Iowa, where he met his wife of 42 years, Dorothy, and received a doctorate in mechanics and hydraulics.
IMPORTANT NAVY PROJECTS
IN 1951 he began working for the navy as a civilian, studying how to improve the ships and submarines. He was promoted quickly after correctly predicting and helping solve a structural problem with the Navy's first nuclear-powered submarine, the Nautilus.
After serving as chief scientist for the Navy's special projects office, where he helped develop the Polaris missile, Dr. Craven in 1963 became the head of the Navy's Deep Submergence Systems Project. There he pioneered advanced vehicles for deep-ocean research, rescue and salvage. He and his team played important roles in major political crises. In 1966 he helped find an American hydrogen bomb that had been lost off the coast of Spain and in 1968 helped locate the twisted wreckage of a nuclear-powered attack submarine, the Scorpion, in waters nearly two miles deep.
The fleet of underwater vehicles that he helped develop include the Navy's NR-1, a deep-diving nuclear submarine with crab-like claws for picking up objects; the Deep Submergence Rescue Vehicle, a cylindrical that could save up to 24 people at a time from a sunken submarine; and the bathyscaphe Trieste, a deep diving vessel that his team improved to increase its operational range. It investigated the sunken Scorpion.
Dr. Craven was lured to Hawaii in 1970 by the state's governor, becoming dean of marine programs at the University of hawaii and the state's marine affairs coordinator.
IMPETUS FROM OIL EMBARGO
A major challenge arose in 1973 when the Arab oil embargo sent petroleum prices spiraling and touched off a frenzied search for energy alternatives. The price shock hit especially hard in Hawaii, which depends heavily on imported oil.
In 1974 Dr. Craven founded the Keahole site, known as the Natural Energy Laboratory in Hawaii. It was a state research center for the study of conventional ways to produce power, especially ones that tapped the site's abundant supply of sunlight and cold water. In 1979 the lab undertook its first major test when a converted tanker off Keahole Point extended a two-foot pipe down some 2,700 feet. Its novel machinery was a big success, generating 50 kilowatts of gross power. Subtracting the electricity used to run the water-lifting pumps, the rig produced 15 kilowatts of surplus power.
"It seemed like perpetual motion," Dr. Craven recalled. "We had no fuel but it kept running. Watching it work was an incredible experience."
Fifteen kilowatts is no great crackle of electricity by commercial standards, being just enough to power a single modern household. But the experiment demonstrated for the first time anywhere the net production of electrical power from OTEC (pronounced Oil-tek), or ocean thermal energy conversion.
This approach, whose working principle was first envisioned in the 19th century, uses the world's largest collector of solar energy, the ocean, to heat a fluid that rotates a turbine and generates electricity.
It works in one of two ways. Warm surface water in an evacuated chamber boils and generates vapor that rushes through a turbine as the vapor is colled by frigid seawater and condenses back into liquid, a method known as an open system. Or the warm surface water vaporizes a working fluid such as ammonia that drives the turbine. Cooled ammonia is recycled in what is known as a closed system. In both cases, a temperature gap of about 35 degrees or more makes possible the production of net power.
Dr. CraVen's ship used a closed-cycle system, which was more compact. But as his lab laid a series of pipelines from the shore into the sea in the 1980's, tests of open-cycle systems were also conducted. As a by-product these produce a flood of desalinated water fit for agriculture or human consumption, since salt is left behind as ocean water turns to stream.
Today, the world's newest OTEC system is the $12 million, 43-foot tall cylindrical power tower here, which is producing 210 kilowatts of electricity and about 50 kilowatts of surplus power. This open-cycle system came to life in January, aNd engineers here are now working to increase its running time slowly from eight hours at a stretch to continuous production. The aim is to gather solid operational data for two years.
The project is financed by the State of Hawaii, the Federal Government, and a not-for-profit consortium in Honolulu that has been supported by the Japanese Government.
With new kinds of turbines, an open-cycle system might scale up to plants no bigger than about 10 megawatts since efficiency is limited by the low-pressure steam. A closed-cycle system could in theory be as large as 100 megawatts (and would require a cold water pipe 60 feet in diameter or an equivalent collection of smaller ones). By contrast, a large nuclear reactor can produce 1,100 megawatts of power. An OTEC plant, though small by world standards, is attractive because its fuel is free and clean.
`WATCH THE STUFF GROW'
Dr. Craven and his crew in the 1980's began experimenting with aquaculture, finding that nori, the seaweed used to wrap sushi rolls, would increase its mass at a rate of 55 percent a day.
"You could literally watch the stuff grow," he said. "We were astounded."
The cold seawater is rich in organic nutrients like nitrates, phosphates and silicates, is almost devoid of pathogens since it comes from so far below the life zone found near the ocean's surface, and is very clean since it has been out of contact with the surface for centuries. Today, the mixing of warm and cold waters at the Keahole site allows temperatures to be tailored for the manipulation of growth and reproductive cycles.
Private companies line the main road here. The Cyanotech Corp. Has 600-foot raceways filled with microalgae from which it extracts fluorescent diagnosis. It also grows microalgae that serve as food supplements.
Kona Cold Lobsters Ltd. Raises lobsters, 25,000 of them at the present time. "There's no lobsters out there," said Phil Wilson, a company vice president, gesturing toward the nearby Pacific, "only in here."
The half-acre plant is both a holding tank for lobsters flown in from Maine for distribution here and the Pacific rim, and a maternity ward where experiments are under way in hybridization and growing tiny eggs into giant crustaceans.
Company buildings, like those of the lab, are air-conditioned by the cold water. Indeed, air-conditioning turns out to be one of the most economically attractive uses of cold water. It is easy to achieve technically and pays for itself rapidly.
Dr. Craven says a tenant researcher at the lab devised the technique in the mid-1980's, piping cold water through an automobile radiator and having a fan distribute cool air.
Clare Hachmuth, executive director of the Keahole site, said the lab now saves $1,300 a month on electricity by using cold water to cool its two major buildings.
Dr. Craven, who no longer holds a post with the lab but instead acts as an elder statesman, says that what he prides himself on most in the course of a long oceanic career is learning how to innovate despite the frequent appearance of social obstacles.
"You can't do it if you stick to a big plan developed by the Harvard Business School," he says, "You've got to be a Brooklyn boy. You've got to sneak up on the thing."
Back to Common Heritage Corporation media page.