Verdant's turbines require tides that move at least six feet (1.8 meters) per second in order to generate enough energy for them to be cost-effective, and the East River is more than obliging. "The East River is a good tidal channel that links the Long Island Sound to the ocean," says Trey Taylor, the company's president and head of market development. "Plus, New York is an expensive place to buy power, so it would be easier here to prove that this could help."
Verdant plans to next year test a new type of turbine in Canada on the Saint Lawrence River, near Cornwall, Ontario, that is heavily weighted and sits on the riverbed rather than being moored to the bottom. These two turbines are expected to generate more than 120 kilowatts of energy and will be easier for the company to remove when repairs are needed. (They have to wait for slack tide to do any work on the turbines in the East River.)
The East River site produced nearly 50,000 kilowatt-hours of energy from December 2006 to May 2007, and the testing spot has the potential to support as many as 300 turbines and nearly 10 megawatts of installed capacity. By 2010, Verdant's hope is to increase its turbine farm in New York City to 30 devices producing more than a megawatt of energy (800 households use about one megawatt). The company is also looking at sites in China and India.
Verdant is the main player in a market trying to catch on. Another tidal power company, East Yorkshire, England–based Lunar Energy, in March began working with Korea Midland Power Company to create a giant 300-turbine field in the Wando Hoenggan Water Way off the South Korean coast. The plant is expected to provide 300 megawatts of renewable energy to Korea Midland Power by December 2015. Researchers at Florida Atlantic University's Center of Excellence in Ocean Energy Technology in Dania Beach are using a $5-million state research grant awarded in late 2006 to develop technologies that tap into the powerful Gulf Stream and take advantage of large water temperature differences off Florida's shores. The researchers envision thousands of underwater turbines producing as much energy as 10 nuclear power plants and supplying one third of the state's electricity.
The U.S. government has made it clear that advanced water-power projects are a priority. Including its plans to help Verdant, the Energy Department in September said it would dole out up to $7.3 million over the next five years to advance commercial viability, cost-competitiveness and market acceptance of new technologies that can harness renewable energy from oceans and rivers.
It is unclear just how much it will cost to tap into energy from large bodies of water. Verdant's Taylor says his company is at least two years away from being able to quote costs to potential customers. That said, a rough cost estimate for Verdant's marine renewable energy technology is up to $3,600 per kilowatt—a higher price tag than wind power, fossil fuels or hydroelectric dams today, he says. He also points out, however, that Verdant will be able to lower its costs over time through the mass production of its technology and the reduction of inefficiencies in the licensing and implementation processes.
Verdant, which operates its kinetic (non-dam) hydropower project in the East River under a preliminary permit from the Federal Energy Regulatory Commission (FERC), plans to by the end of the year apply for a FERC pilot commercial license that would allow the company to create a field of up to 40 underwater turbines with up to 1.5 megawatts of capacity. It took four years to secure the necessary permits from the New York State Department of Environmental Conservation and the U.S. Army Corps of Engineers to get the project to where it currently is. Verdant has spent at least $9 million thus far on its East River project; one third of funds were spent on studies to gauge the potential impact of the turbines on vessel navigation, aquatic life and fish migration.
Taylor hopes to eventually have two fields of underwater turbines in the East River with a total installed capacity of up to 10 megawatts. Other opportunities abound throughout New York State, he adds. "One estimate predicts as much as 1,000 (megawatts) of potential installed capacity for the state," whose State Energy Research and Development Authority (NYSERDA) chipped in $3 million toward the East River project. "With a commercial license issued, and with the field built, we will continue with operational tests, generating and delivering grid-connected power to paying customers."