Energy From Rivers – New Ideas For Tapping This Source

We have had water mills to help do farm chores, we have had hydroelectric dams to harness and create energy from water but these have either been too small (mills) to do much good for our energy needs or they are too disruptive (dams) of the river environment. Now scientists are looking into new and innovative ways to harness the power of flowing water in such a way as to be scalable and useful for societal energy production as well as unobtrusive or damaging to the environment. This article tells the story of one such promising technology.

Don’t be fooled by Ol’ Man River. Below the surface of even the laziest stream surges an eternally youthful source of energy—water coursing its way from the highlands back to the ocean in a driven, ineradicable flow.

The energy is there but tapping it is difficult. Water mills did their small part to ease chores like grinding wheat into flour. And on a larger scale, hydroelectric dams provide energy for entire towns. But they interrupt essential dynamics of the river, stanching the flow of essential nutrients to portions of the river downstream, and disrupting the reproductive habits of fish that time their spawning to yearly floods.

University of Michigan Professor Dr. Michael Bernitsas in front of Vivace. Photo/Scott Galvin, U-M Photo Services

Michael Bernitsas, a marine engineer at the University of Michigan has added his own invention to this timeline. He predicts that his system will convert river currents into large amounts of power without altering natural structures or even being visible from the surface.

Bernitsas’ Vortex Induced Vibration for Aquatic Clean Energy converter, or VIVACE, is driven by a rig of cylinders running parallel to the bed of a river. Each cylinder is mounted on a spring-loaded runner, giving it a vertical motion. In a current, the cylinders plunge up and down like a robot marching in place. “It’s like a reciprocating engine with four cylinders. But they are driven by the fluid dynamics” of the river, says Bernitsas.

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