A Wave of Watts

It's a stormy morning in New York City, and Trey Taylor is supposed to be watching a big blue turbine submerge into the East River. Taylor is the president of Verdant Power, an energy startup embarking on a project that aims to do nothing less than change the national discussion on clean energy. On the bed of the river, which is actually a tidal strait, the company has installed six turbines. The sleek devices resemble modern windmills, except these are designed to pivot with the tides, like a weather vane in the wind, generating electricity as the water spins the blades.

When the project first went on line last year, it was heralded as the world's first tidal power project to deliver electricity to customers -- in this case, a Gristedes supermarket and a parking garage. But there were immediate problems. Days after the first turbines were lowered into place, the forceful current snapped the fiberglass-and-steel blades. The broken rotors had to be replaced with sturdier aluminum blades. Then last summer, the project had to be halted because the bolts connecting the blades to the central shaft began to break under the immense strain of the East River's tidal rip.

Now, the underwater energy project is getting a third try. Looking out at the river from Roosevelt Island, Taylor is eager to get the redesigned turbines back in the water. But the skies open up and a torrential thunderstorm begins to pour down. The unexpected deluge means the installation will have to be postponed. As sheets of rain pelt down on the river, Taylor beams, undaunted. "Well, tomorrow's supposed to be a beautiful day. We'll get it in there!"

If tidal power has suffered some setbacks, it's what you might expect from technologies that are still very much in the experimental phase. But there are good reasons to press on. Just the one site under the East River, if man can finally master its tides, could eventually support as many as 300 turbines, producing enough power for about 8,000 homes. (As of a few weeks ago, the pilot project seemed to be running smoothly again.)

Tidal energy is just one part of an emerging field collectively referred to as "hydrokinetic energy." The idea is simple: to harvest the natural energy flowing through rivers and oceans, whether it's from tides, currents or even the gentle roll of waves. The concept is similar to other "passive" technologies such has hydroelectric dams and windmills. But hydrokinetic energy has two key advantages over its zero-emissions cousins. First, it's less environmentally destructive than damming up rivers and streams, as was commonly done in the 20th century. And underwater turbines are easier to site than windmills, which, whether they're proposed on land or offshore, tend to draw opposition from people who don't want to look at them.

Indeed, interest in hydrokinetics has exploded in just the past couple of years. The Federal Energy Regulatory Commission issues permits for all grid-connected hydropower projects in the country. In 2005 and 2006, FERC issued a total of four permits for hydrokinetic pilot projects. In 2007, the agency issued 33 permits. By the middle of this year, FERC had already approved 77 permits and another 81 more were pending approval. Hydrokinetic projects are on the drawing board from Martha's Vineyard off the coast of Massachusetts to the rivers of Alaska. One of the largest is a $3 billion plan to install thousands of small turbines in the Mississippi River, from St. Louis to the Gulf of Mexico. The company leading the project says its turbines would collectively generate enough energy to power 1.5 million homes.

The new forms of hydropower are beginning to get the attention of state and local governments. The New York State Energy Research and Development Authority estimates that tidal and in-stream turbines in New York State alone could produce enough energy to power about 800,000 homes. The authority has contributed $3.5 million to Verdant's East River initiative -- about one-third of the project's price tag so far. New York City has given another $750,000. Jim Gallagher, energy director for the city's economic development corporation, says he's not deterred by the technological setbacks. "We knew all along that it was a research-and-demonstration project. For us, one of the major objectives was simply to answer the question of whether tidal power in the East River is even feasible."

Bobbing for Power

Oregon is another incubator of hydrokinetics. In Oregon, however, the interest is in capturing energy from ocean waves, rather than the tides. Oregon offers energy companies a tax credit for investing in wave power. And last year, lawmakers established the Oregon Wave Energy Trust, a nonprofit organization that acts as a clearinghouse for the nascent wave-energy industry. Funded this year with $4.2 million in seed money from the state, the trust works to attract wave projects and accelerate the commercialization of technology in the state.

The Oregon coast is a veritable research-and-development lab for the industry. The projects under design take different approaches, but all seek to reap power from the irregular undulations of the Pacific Ocean. One does this using a floating buoy that converts up-and-down wave action into electricity and sends it back to shore via underwater cables. Another is a jetty-mounted device that captures wave power as it hits the shore. A third uses waves to move electrical coils through a magnetic field, generating electricity. The diversity of projects demonstrates just how new the field of wave power really is. "It's very, very early in the industry," says Stephanie Thornton, executive director of the Oregon trust. "We just don't know which technologies are going to work out. But we're going to get there."

Hydrokinetics may seem promising, amid debates about fossil-fuel dependency, greenhouse-gas emissions and offshore oil drilling. But this new generation of technology raises its own set of environmental questions. The one that gets raised most frequently has to do with fish. Will thousands of blades whirring away in the sea or at the bottom of a river pose a threat to marine life?

That's the concern of Janet Sternburg, policy coordinator for the Missouri Department of Conservation. After FERC approved more than a dozen new projects in the Mississippi River last year, Sternburg sent the agency a letter expressing her misgivings about potential adverse environmental effects. "This is new technology," Sternburg says. "We're just not sure what this might mean for fish in the area. Of course green energy is a big, important issue. It could be great. It also could be problematic depending on where it's placed and the nearby resources."

According to Trey Taylor, fish and turbines have been getting along just fine in the East River. Fish don't even seem to notice the turbines, Taylor says. And the ones that do simply swim around them. Still, new hydrokinetic projects are subjected to a fairly rigorous environmental review, and require approval from state regulators, in addition to a raft of federal agencies.

Ultimately, Taylor says, hydrokinetic energy is adaptable enough to adjust to the environmental concerns that have been raised. If a problem with fish or anything else were to arise in one place, it wouldn't be all that hard to remove the equipment. "Dams are permanent," says Taylor. "But turbines or buoys are easy to change or remove. If for some reason you do find there's an environmental concern, then you just take them out of the water."