Experts at the Federal Energy Regulatory Commission are taking a cautious look at 123 applicants who want to generate renewable energy underwater, using a relatively untested technology.
The technology in question is called hydrokinetic. Like the turbines in dams, hydrokinetic turbines generate power from the movement of water. But these turbines don't need dams and don't present some of the challenges and expenses that come with them, explained Ed Lovelace, executive vice president of engineering at Free Flow Power, based in Gloucester, Mass.
The turbines work by capturing the energy of flowing water, which they pick up from waves, tides and currents. Because water has greater density than air and flows are more constant than wind, underwater turbines can deliver much more energy than wind turbines.
In the past few years, more than 100 proposals for hydrokinetic projects have been filed with FERC. On average, the projects include clusters of 20 or more turbines. Free Flow Power is behind 88 of them, which are slated for the Mississippi River Basin between St. Louis and Gulf of Mexico. Proposed locations from other companies include ocean coasts, where turbines can capture tidal action.
This rush to development is prompted by hydrokinetic's potential to produce renewable energy on a large scale in places where it can easily connect to the nation's power grid, Lovelace said. The Mississippi River offers a massive resource, drawing water from a drainage area that covers about 40 percent the total area of the lower 48 states in the United States.
But placing a mechanism that is similar to a wind turbine in the water could have its consequences. Turbines can be insulated well so they do not leak electricity, but they still generate small electromagnetic fields around them. They also may be loud, and noise travels farther and faster underwater and could impair wildlife.
Drawn-out licensing procedure
FERC has kept most of these projects at a slow pace by requiring that companies go through multiple stages of scrutiny before getting a green light.
Before FERC can grant a license, companies have to apply for permits that give them priority over a site. Once granted, the permits give the company in question priority over a site for up to three years. This period lets the companies study the site for feasibility of the technology. They also have to prove the projects will minimize harm. If the company likes the site, it can next apply for a license through FERC that would allow power production on it.
For each permit proposal, FERC does an environmental review and takes in public opinion. The regulatory agency also grants shorter "pilot" licenses as an alternative to streamline the process. While FERC's conventional hydropower licenses can last 40 to 50 years, pilot licenses cut that down to five years. Part of this is because regulators want to be cautious with relatively untested technology.
"FERC has to be convinced these can generate electricity in safe matter," said Glenn Cada, a researcher at the Oak Ridge National Laboratory. "The licenses have a provision in them that if something unexpected happens, FERC can remove [the turbines]."
In the years since applications started hitting the agency, it has granted only one license to a project that would have generated power from waves on the coast of Washington state. That was back in December of 2007, and the company behind it, Finavera Wind Energy, has since surrendered its license, said FERC spokeswoman Celeste Miller.
In 2008, FERC also allowed Hydro Energy Green, a company based in Hastings, Minn., to put two 35-kilowatt turbines in the Mississippi River. At the time, the city of Hastings had already had a conventional hydroelectric FERC license. Hastings asked FERC to allow the hydrokinetic turbines to operate by adding them as an amendment to its conventional license. FERC allowed it, and the Hydro Energy initiative became the first in the country. To date, they're the only hydrokinetic turbines generating power to the grid.