Ocean Power Can Be a Global Warming Cure

How shall we ever slake our ever-growing demand for electricity? Even as concerns about global warming escalate, are we doomed to create more of the same old polluting, coal- and oil-dependent power plants? Or can common sense -- and some radically new technologies -- serve us better?

There’s much talk of wind and solar power. But how about the oceans and their massive tidal and current patterns? Driven by the gravitational force of the sun and the moon, tides and currents represent a source that’s as infinite and everlasting as any force on earth.

A major pilot demonstration seems ready to launch in San Francisco Bay, where an immense tidal flow enters and exits every day at a narrow point of the Golden Gate. A gigantic energy-collection device vaguely reminiscent of a Ferris wheel, with a number of fins (or “wings”) to capture the power of the rapidly passing tides, will be lowered from a barge anchored in the narrows. Using maglev technology, it will produce electrical energy that can then be transmitted to shore by cable.

If the San Francisco experiment works, the way could be opened to vast “farms” of underwater energy generators, operating below the ocean surface off Florida’s Atlantic Coast and along such shorelines as New England and the Pacific Northwest. A major early target could be in the Gulf Stream as it flows between Florida and Bermuda, where the 6.1-mile-per-hour current is 23,000 times the magnitude of the river flow at Niagara Falls.

Dan Power, the former Air Force engineering officer who is president of Oceana Energy, a firm recently organized to develop tidal current power systems, says it’s too early to project the percentage of power needs the new technology could deliver. But along America’s heavily populated coasts, tidal currents could, he believes, become “a major future power source.”

First comes the next year focused on the San Francisco experiment, as Oceana works with engineers of the U.S. Navy’s Hydromechanics Directorate, local utilities and governments to model, test and install the pioneering generator at the Golden Gate.

Contrast that with last week’s estimate that over 150 coal-powered power plants, most powered by dirty, last-generation technologies, are now being planned by U.S. energy companies. The estimate, by U.S. PIRG, the national association of state Public Interest Research Groups, is based chiefly on information from the U.S. Energy Department. Already, quantities of the coal-fired plants are being announced, including 11 by TXU Corp. in Texas alone.

What will be the impact of all the new plants? A stunning 10 percent increase in U.S. global warming emissions, U.S. PIRG estimates -- at the very moment the United States, now responsible for over 30 percent of global greenhouse gas emissions, should be reversing course, leading rather than hindering worldwide efforts to avert potentially catastrophic global climate change in this century.

Yet applying the same $137 billion the energy companies plan for coal-fired plants to energy conservation, U.S. PIRG calculates, would reduce our energy demand by 19 percent in 2025 -- obviating the need for all the new plants. Comparable investment in wind farms or solar power could also go far to obviate the need for the new coal plants (only 16 percent of which are projected to use new coal gasification technology).

But now comes ocean tidal power recovery -- a technology that Power claims is so benign it wouldn’t even impact fish life.

In one sense the idea of tapping tidal energy isn't new; even Ben Franklin, on his trans-Atlantic voyages, noticed the current and speculated on converting its power for human purpose. But not until recent advances in magnets as well as plastics that can protect underwater metal devices from corrosion has the technology become feasible.