BY ELAINE LAFAY
Daily Staff Reporter
Published November 14, 2007
A University professor has developed new technology that he says will extract energy from water in an environmentally-friendly way. It's slated to be deployed in the Detroit River over the next 19 months.
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Michael Bernitsas, professor of naval architecture and chief executive officer of Vortex Hydro Energy, says his device -VIVACE, which stands for Vortex Induced Vibration for Aquatic Clean Energy - presents "a totally new method of extracting energy from water flow."
The device in the Detroit River would consist of a series of cylinders that would vibrate because of the water rushing past them. The rushing water creates a spinning pocket of water: a vortex. The energy given off by the vortex is then harnessed and used to generate electricity.
"To some, the idea of VIVACE may seem exotic, but in water it's the natural thing to do," Bernitsas said.
That's similar to the way a school of fish moves through water. Fish at the front of the school create vortices as they swim by curving their bodies back and forth. Then the fish following them use the same motion to push off of vortices and propel themselves.
And backers of the technology say fish will be one of its beneficiaries.
John Kerr, director of economic development at the Detroit/Wayne County Port Authority, said VIVACE said other hydroelectric technologies include underwater turbines, which operate like underwater windmills and have harmed fish.
But Kerr said VIVACE won't do that.
"The worst-case scenario with these cylinders is that fish get disoriented for a little bit," he said.
VIVACE extracts energy from the currents in the river, but part of what makes it groundbreaking is its ability to extract energy from currents at lower speeds, unlike other technologies.
According to the Electric Power Research Institute, turbines and water mills need an average current speed of 5-7 knots - or about 6-8 miles per hour - to be financially viable.
Most currents flow at speeds of less than three knots. VIVACE allows access to those currents for energy.
"Currents are a reliable source of energy," Bernitsas said. "Waves, solar power and wind are often unpredictable."
Bernitsas said water is the largest medium that absorbs energy, most of which comes from the sun. If humans could harness just 0.1 percent of that energy, he said, it would cover the needs of 15 billion people.
The device took Bernitsas and others about three years to develop and will be used to power a 20,000-square foot building on the Detroit River.
Kerr said he expects for the Detroit River to be a good demonstration site for Bernitsas' technology because it is deep and has a relatively strong current.
Bernitsas and his team plan to finish a feasibility study by the end of this year. As long as the results are what they expect, about 18 months will be spent putting the device in the Detroit River.
The Detroit/Wayne County Port Authority is helping fund the project along with the DTE Foundation, an electric company. In addition to the $400,000 received so far, Bernitsas's company expects to raise another $3-5 million in funding.