Low water stalls river turbine plans
Firm cancels clean-energy project after 2012 drought
The drought of 2012 may be over, but it had one lasting effect: It dried up all the enthusiasm for a $3 billion clean-energy project designed to harness the power of the Mississippi River.
Free Flow Energy Corp. had planned to mount power-generating turbines on pilings sunk in the river bottom near Memphis and other sites. The Bostonbased firm obtained preliminary permits and hosted public meetings on the initiative.
But after five years of study and preparation, Free Flow this month told the Federal Energy Regulatory Commission it want- ed to surrender the permits. In a letter to FERC, the company said it conducted a feasibility study and “concluded that pursuing development of the Projects at this time is not viable.”
Dan Lissner, general counsel for Free Flow, cited the “challenging river conditions” during last year’s drought as a major factor in the decision. “That forced us to take a step back and look at the totality of the project,” he said.
Free Flow was seeking federal licenses to install some two dozen turbine sites between Kentucky and Louisiana that would generate a total of 3,303 megawatts of power, or nearly five times the output of the Tennessee Valley Authority’s Allen Fossil Plant in Memphis. In all, the company had obtained more than 50 preliminary per- mits from FERC to develop the project.
Unlike traditional hydroelectric facilities, which use the falling water from dam discharges to turn turbines, the “hydrokinetic” units envisioned by Free Flow would generate power by having the natural current of the Mississippi — often more than 6 mph — spin the turbines.
But with each turbine having
a diameter of about 10 feet, and with barges requiring at least 9 feet of water, depths would have to more than 20 feet at each site. Although some spots on the Mississippi have constant depths of 80-plus feet, the prolonged dry weather last summer left long stretches of the river barely deep enough for barges, let alone turbines.
The drought, the worst in the U. S. in more than half a century, sent the river plummeting to stages as low as minus-9.86 feet at the Memphis gauge — less than a foot above the record of minus-10.7 feet set in 1988.
Although the river remained sufficiently deep for a limited number of turbines, Lissner said that for the initiative to be profitable, the firm had to take a “scale approach” — benefiting from economies of scale by employing dozens of turbine sites.
“This is far from a statement that hydrokinetics on the Mississippi River is not feasible,” he said.
During public meetings they hosted in 2009, Free Flow officials fielded questions about issues ranging from the effects of the turbines on navigation to the likelihood of fish being killed or injured by the blades.
“All along, one of the main concerns was making sure there’s sufficient water for their turbines and barge traffic,” said Roger Allan, a biologist with the regulatory branch of the Corps of Engineers’ Memphis district.
With the death of the Free Flow initiative, there are no proposed hydrokinetic projects proposed in the Memphis area, Allan said, although one firm might try to install turbines below Helena, Ark.
Still another f i rm, Hydro Green Energy, plans to generate power by putting turbines at existing locks and dams on waterways that include the Mississippi River in the Midwest, the Arkansas River and the TennesseeTombigbee Waterway.