Harnessing energy from the sea
Aboard the SS Ocean Energy Converter
It's a strange place for an electrical power plant -- floating at sea some 18 miles and a two-hour boat ride from the big island of Hawaii. But that's exactly why this old Navy oil tanker is here -- to prove that the electricity for 1,000 homes can be generated from these sapphire-blue Pacific waters.Skip to next paragraph
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This still-developing form of power from the sea is called ocean thermal energy conversion (OTEC) an awkwardly long and intimidating name for a project now endangered by a budget-conscious Reagan administration.
Technical semantics and politics aside, however, OTEC is based on a simple energy conversion principle that engineers involved with it say eventually could provide tens of thousands of megawatts of renewable electricity from a renewable energy source -- one that light supply electricity for island markets by the end of this decade.
Although the world's oceans, covering 71 percent of the globe, are only one of the many resources available to mankind, energy experts say they are abundantly rich -- in theory at least. The sea, however, is a particularly hostile frontier. The very forces engineers seek to harness -- waves, salt, and tides -- can snap man-made structures as though they were pick-up sticks or corrode all but the most expensive metals known.
But the search for ways to tap Neptune's power progresses. It is a broad-based hunt, which some expert say should focus on an energy source which, although not renewable, is thought to be plentiful -- offshore oil.
The United States Geological Survey has estimated that between 12.5 billion and 38 billion barrels of undiscovered, recoverable oil lie beneath the US outer continental shelf (OCS) -- a hefty potential compared with the country's proved reserves of 27.1 billion barrels of crude oil.
To date, only minimal drilling has been attempted. Of the 578 million acres of OCS land under federal government control, less than 4 percent of that total has ever been leased to oil companies. Only 2 percent currently is under lease.
Although the drilling so far has yielded mainly "dry" holes, oil company executives contend that if there is a last oil bonanza to be discovered in the United States one of the most likely places to find it is beneath the sea. The best way to get that oil, they argue, is to step up the pace of offshore leasing -- a strategy they hope an apparently sympathetic Reagan administration will support.
But of all the possible energy resources of the sea offshore oil drilling is the most controversial. Environmentalists, who charge that oil companies lack the technological experience to drill safely in deep waters, have fought long and hard to protect ecologically sensitive ocean tracts. They are not expected to surrender now.
Even as this much-publicized fight continues, however, scientists and engineers are charting calmer waters as they seek out the ocean's energy potential.
Among the more promising resources they are studying is wave power. The United States, Great Britain, and Norway are all experimenting with wave projects. The Japanese already have built an experimental barge carrying a wave-fed turbine that generates electricity for transmission to shore.
There are also energy resources in the tides, which have an estimated potential for replacing 1 billion barrels of oil on a worldwide basis. The French already have proved this power can be tapped; since 1967, they have operated a 240-megawatt tidal-powered plant on the La Rance estuary.
Engineers also are studying the possibility of capturing the energy created where freshwater rivers meet the ocean, a process known as salinity gradient. In theory, they say, if all this power could be converted, it would supply 10 percent of the world's present energy demands.