VIVACE: 'fish' inspired energy device captures power from slow moving currents

November 22 2008 / by Garry Golden
Category: Technology   Year: Beyond   Rating: 3

The thermal and kinetic energy potential of the world’s oceans remains largely untapped by energy producers. Earlier we featured a new Lockheed pilot project in Hawaii that evolves the once novel idea of capturing ocean thermal energy conversion into clean electricity. What other power generation schemes might emerge from our oceans?

What happened?
University of Michigan engineer Michael Bernitsas has made a machine that works like a fish to turn potentially destructive vibrations in fluid flows into clean, renewable power.

The machine, called VIVACE, is being developed by Vortex Hydro Energy as the first known device that could harness energy from most of the water currents around the globe because it works in flows moving slower than 2 knots (about 2 miles per hour.) Most of the Earth’s currents are slower than 3 knots. Turbines and water mills need an average of 5 or 6 knots to operate efficiently.

VIVACE stands for Vortex Induced Vibrations for Aquatic Clean Energy. The array of devices doesn’t depend on waves, tides, turbines or dams. Instead it is a unique hydrokinetic energy system that relies on “vortex induced vibrations” that have damaged bridges for decades. Rather than try to avoid damage by these vibrations, VIVACE captures the motion power by mimicking the movement of fish.

The concept model of VIVACE looks nothing like a fish, but future versions should have the equivalent of a tail and surface roughness a kin to scales. The working prototype is one sleek cylinder attached to springs that hangs horizontally across the flow of water in a tractor-trailer-sized tank in his marine renewable energy laboratory. The water in the tank flows at 1.5 knots.

Bernitsas estimates that an array of VIVACE converters the size of a running track and about two stories high could power about 100,000 houses. Such an array could rest on a river bed or it could dangle, suspended in the water. But it would all be under the surface.

*Why is this important to the future of energy?

The world is expected to double its energy consumption in the coming decades. Much of that energy production must come from low cost abundant resources that fit within an increasingly carbon-constrained regulatory marketplace.

It is difficult to estimate costs of a commercial scale versions of VIVACE, but Bernitsas estimates 5.5 cents per kilowatt hour compared to wind energy (6.9 cents), nuclear costs (4.6 cents), and traditional solar power costs (16 and 48 cents) ‘depending on the location’.

The next step will be developing a working version of VIVACE. The research team has completed a feasibility study that found the device could draw power from the Detroit River and are working to deploy one for a pilot project there within the 18 months.

According to Bernitsas “There won’t be one solution for the world’s energy needs, but if we could harness 0.1 percent of the energy in the ocean, we could support the energy needs of 15 billion people.”

Eureka Alert Press Release

Artist’s illustration of an array of VIVACE converters on the ocean floor. Illustration credit: Omar Jamil

This work has been supported by the U.S. Department of Energy, the Office of Naval Research, the National Science Foundation, the Detroit/Wayne County Port Autrhority, the DTE Energy Foundation, Michigan Universities Commercialization Initiative, and the Link Foundation. The technology is being commercialized through Bernitsas’ company, Vortex Hydro Energy.

For more information: Michael Bernitsas Vortex Hydro Energy

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