Swim Like the Fishes

Researchers at the University of Michigan have been working on a way to harness slowly ocean and river currents (1 to 2 knots), and have a solution, according to Britain's Telegraph (via huffingtonpost.com).

Called Vivace, or "vortex-induced vibrations for aquatic clean energy," the system is inspired by the way fish swim, and consists of "a system of cylinders positioned horizontal to the water flow and attached to springs. As water flows past, the cylinder creates vortices, which push and pull the cylinder up and down. The mechanical energy in the vibrations is then converted into electricity."

Some choices quotes from the Telegraph:

A "field" of cylinders built on the sea bed over a 1km by 1.5km area, and the height of a two-storey house, with a flow of just three knots, could generate enough power for around 100,000 homes.

...generating power in this way would potentially cost only around 3.5p [pence] per kilowatt hour, compared to about 4.5p for wind energy and between 10p and 31p for solar power.

Michael Bernitsas, a professor of naval architecture at the [University of Michigan], said..."If we could harness 0.1 per cent of the energy in the ocean, we could support the energy needs of 15 billion people." [!!!!]

Because the parts only oscillate slowly, the technology is likely to be less harmful to aquatic wildlife than dams or water turbines. And as the installations can be positioned far below the surface of the sea, there would be less interference with shipping, recreational boat users, fishing and tourism.

A test installation is planned for the Detroit River, which moves just under 2 knots. I assume much attention will be paid to the environmental impact of the test system, but I'll be on the lookout for updates over the next few years on this exciting possibility.