Clean energy from rivers

'' Whirligigs of illuminated particles form as the water pours over and under the cylinder in rhythmic patterns.

It looks simple, but it's revolutionary. This is VIVACE, a device to harness energy in slow-moving water currents across the globe and turn it into electricity.

VIVACE, which mimics the way fish swim in currents, is to debut next year in the Detroit River, powering the light for a new wharf between Hart Plaza and the Renaissance Center.'' [source and source]