A raft of startups has set out to harness energy from waves and tides, many of them in the turbulent waters of Scotland’s Pentland Firth. A subset of that group has emerged in recent months with plans (and prototypes) for tapping river flows.
Rivers have powered grist mills since before Mark Twain sent Huck Finn afloat on the Mississippi, and the Great Miami River even generated electricity for some early Ford (s F) factories. But mounting political pressure to develop alternative sources of energy has sparked new interest — and investment — in river power technology that’s far less obtrusive than the hydroelectric dams that now generate about 10 percent of electricity used in the United States. Companies like the five below are leading a new wave of river power, or hydrokinetic, technology.
Free Flow Power: Massachusetts-based Free Flow Power has its eye on the Lower and Middle Mississippi River for turbine arrays that can be mounted to free-standing pilings or existing docks and piers. The company secured its first preliminary federal permits from the Federal Energy Regulatory Commission at the beginning of this year, winning exclusive rights for three years to evaluate sites from St. Louis to the mouth of the Mississippi. It’s now studying 55 sites for a 1,600 megawatt, $3 billion project.
Verdant Power: Selected as one of six teams to receive DOE funding for water power technology development, Verdant Power is negotiating an award (up to $600,000 for a max of two years) to develop a larger, higher-power turbine blade system and streamline the manufacturing process. The New York-based startup began testing turbine prototypes, first made of fiberglass and steel, and then aluminum and magnesium, in the East River (technically a tidal strait, not a river) two years ago. Verdant bolted its latest prototypes, made from an aluminum alloy, to the riverbed in September. If these turbines hold together, company president Trey Taylor has told the Washington Post, Verdant expects to apply for permits to launch a commercial operation. Smooth sailing is hardly guaranteed, however. Planned installations in Cornwall, Ontario, were delayed last week after an important investor pulled out, despite more than $2.2 million in funding from the Ontario government.
Hydro Green Energy: This Quercus Trust-backed startup plans to generate 5 gigawatts of energy from two rivers (and some wind) in the Gulf of Mexico, using its modular, barge-mounted turbine arrays. It also has projects and preliminary permits in Alaska, Maine, Minnesota and New York. According to a recent report from The Hill, the company has also begun lobbying for federal appropriations.
Vortex Hydro Energy: Founded in 2004 to commercialize then-early-stage research from the University of Michigan, this startup found its inspiration in fish, which use natural vibrations in water to propel forward. While engineers typically try to suppress those vibrations, the ocean engineers behind Vortex Hydro decided to exploit them, creating a stationary underwater device (with funding from the U.S. Department of Energy and the Office of Naval Research) that can generate electricity from currents moving slower than 2 miles per hour. According to the researchers, existing turbines and water mills need flow speeds of at least 5 mph to operate efficiently. The completed study appears in this month’s Journal of Offshore Mechanics and Arctic Engineering. Next up, the company says, is a multi-kilowatt field demonstration.
Hydrovolts: Hydrovolts, formerly Puget Sound Tidal Power, specializes in modular turbines that resist debris buildup in rivers and canals. While each turbine generates enough electricity for up to only three average American homes (suggesting potential for areas not connected to a reliable power grid in developing countries), the company says large installations could result in utility-scale generation without altering the water channel.