In the last few decades hydro power has earned itself a bad name. Silting problems, disruption of fish spawning migrations, imminent domain struggles. etc. That has been changing recently—mostly due to the tremendous upside to of this clean, inexpensive, continuously available, form of power generation.
In July 2009, Free Flow began a six-month test of a pilot turbine (a third the size of the planned commercial ones) in the Mississippi, and the company is now testing a commercial-scale prototype in the lab. Free Flow has also received $7.4 million in funding from investors and from the U.S. Department of Energy that will allow it to test its most recent prototype in the Mississippi next year. Free Flow Power is seeking additional funding to test four turbines, each attached to a separate pylon, over a 12-month period, as required by FERC as part of the licensing process.
Free Flow uses a “shrouded turbine” design that channels water through the turbine’s blades. Water passes through a rotor with seven blades that are designed for a slow spin rate to minimize fish strikes. The turbines will be sited 10 or more feet off the riverbed. At this depth, water moves, on average, at one to three meters per second.
One interesting technology is hydrokinetic power which is generated by placing multiple turbines on the sea or river bed and allowing the current to drive the low speed turbines. A company called FreeFlow Power is currently testing in the Mississippi River. If this works as advertised it may be even more beneficial in other large, less navigable rivers.Related: Popular: