Vivace is a new energy technology that gets its name from a phenomenon that engineers have been battling for 25 years. VIV (vortex induced vibrations) destroyed the Narrows Bridge in Washington State in 1940, and the Ferrybridge power station cooling towers in England in 1965. Ironically it is also the same phenomenon that allows schools of fish to swim as fast as they do. Now Dr. Michael M. Bernitsas and researchers at the University of Michigan are turning this ‘threat’ into a resource. Rather than suppressing VIV, Vivace actually creates and then harvests energy from VIV, and it does it all using slow water currents, a previously untapped source of sustainable energy.
Most of the water that covers 70% of our planet flows at less than 3 knots – too slowly to harvest its power using current technology. Wave and tidal turbines require an average of 5 or 6 knots to operate efficiently, as does the timeless watermill. But Vivace, the technology being developed by Dr. Michael M. Bernitsas at the University of Michigan, is designed to operate at currents of less than 2 knots, opening up a world of possible applications from river power and dam replacement to perpetually powered ocean sensors, uninterruptible power for vulnerable coastal facilities, and the supply of electricity to offshore facilities.
In its current configuration Vivace looks nothing like a fish (though Dr. Bernitsas says it likely will in the future) but more like a ladder with round, sliding rungs. Vivace exploits VIV by simply placing this ladder across a slow moving current which causes the rungs to oscillate up and down on springs. The oscillating movement creates mechanical energy which is then converted to electricity. The modules are designed to be reusable and are considered less of a threat to marine life than turbines because of their slow movement.
What will it cost? Estimates are coming in at about 5.5 cents per kilowatt hour. When compared with nuclear (4.6 cents a kilowatt hour) wind (6.9 cents a kilowatt hour) and solar (16 to 48 cents a kilowatt hour) Vivace looks like a serious competitor. Dr. Bernitsas’ company Vortex Hydro Energy is working to deploy a pilot project on the Detroit River within 18 months. Here’s hoping it goes ‘swimmingly’!
+ University of Michigan
+ Vortex Hydro Energy