The Green Technocrat

Ocean waves have been an area of big interest in clean tech for a while now.  There are plenty of design teams out there, working on the perfect tidal turbine, that is, one that can efficiently harness the energy generated by the waves that occur with the ebb and flow of the tides.  A lot of interesting designs are being tested, and several companies are starting to have a bit of success, but there has not been a lot of discussion or design focused on harnessing power from slow moving bodies of water, such as rivers.

Earlier today ScienceDaily reported on an interesting new device that uses the vibrations that occur in fluid flow (i.e. moving water) to generate electricity.  The device, which was developed by University of Michigan engineer Michael Bernitsas, is known as VIVACE - Vortex Induced Vibrations for Aquatic Clean Energy.

The name is quite a mouthful, and despite the acronym the device is neither quick or lively.  Rather, the machine is designed to sit in slow moving water and…well…it just sort of sits there.  The key to how VIVACE works is in its name, Vortex Induced Vibrations.  These vibrations are undulations that are caused by a rounded or cylindrical-shaped object when it is exposed to fluid flow (As an aside air can also be treated as a fluid and it is these vibrations that caused the incredible collapse of the Tacoma Narrows Bridge in 1940.).  These vibrations cause the object to be pushed and pulled in directions perpendicular to the current.  As the device (which is essentially nothing more than a cylinder attached to springs) undulates it transfers the energy from these vibrations into mechanical energy which can then be converted into electricity.

Bernitsas estimates that just a few of these cylinders could generate enough electricity to power an anchored ship, and a large platform the size of a running track could power up to 100,000 houses, with an estimated energy cost of 5.5 cents per kilowatt hour, making it cheaper than coal!

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

Currently, Bernitsas and his team are working on deploying a pilot project in the Detroit River within the next 18 months.