Photo: Verdant Power, Inc.

On 11 December 2006, Verdant Power lowered its first two turbines to the bottom of New York City’s East River, to launch the Roosevelt Island Tidal Energy (RITE) project. The blades recently broke in the river's stronger than expected current.

14 August 2007—The promise of unlimited free energy from the ocean’s tides has companies tripping over themselves to get the rights to the best bits of U.S. coastline. But the number of real opportunities for tidal energy—where incoming and outgoing tides drive underwater turbines—is small. And developers are finding it hard not to stumble over each other or over the U.S. Federal Energy Regulatory Commission’s antediluvian hydropower regulations, which were established back when hydropower meant the Hoover Dam. Now FERC is trying to clear the path and bring tidal energy into the 21st century.

Last month, FERC proposed the second change in a year to its tidal technology licensing system. The new six-month pilot license for tidal projects would largely replace a process that can take up to seven years. But some critics suggest that the commission is facilitating a misguided gold rush.

In 2006, an Electric Power Research Institute study identified five prime North American tidal-energy sites. What makes a prime site? “You need an hourglass-shaped structure,” says Roger Bedard, author of the study and an ocean energy expert at Palo Alto, Calif.–based EPRI. A bay funneling into an ocean through a narrow passage—like the one under San Francisco’s Golden Gate Bridge—puts maximum force into the tides.

Photo: Verdant Power, Inc.

Six turbines like this one provide Roosevelt Island with 1000 kilowatt-hours per day of clean electricity, enough to power a supermarket and a parking garage.

In fact, San Francisco Bay is one of the prime EPRI sites, though the tidal potential of sites in the lower 48 U.S. states are eclipsed by those in Canada and Alaska. However, identifying the site is only the first step in a difficult process. Tidal technology is easy to develop from a technical standpoint, says Bedard, but not from a regulatory perspective.