Wiggling Plastic at River Bottom to Generate Electricity

[Dover]

So glad to see towns and cities taking the initiative!


Wiggling Plastic at River Bottom to Generate Electricity


Aug. 26, 2008 -- For centuries humans have dammed rivers and streams to grind grain and later, generate electricity. Now a new, more subtle form of freshwater power is about to make its debut in the old steel town of Vandergrift, Penn.

Using a grid of electricity-generating smart materials on the bottom of the Kiskiminetas River, combined with a host of energy conservation efforts, Vandergrift hopes to generate between 20 and 40 percent of the city center's electricity.

..snip..


That sustainable power will most likely come from a grid of undulating strips made of polyvinylidene fluoride or PVDF, a material that generates a slight electrical current when it is moved, in this case, by the currents and eddies in the Kiskiminetas River. Such materials are described as piezoelectric, and the resulting electrical current would pass to small substations along the river's edge before charging a group of batteries.

"There are other materials that give better performance or have higher energy densities," said Weiland. "But we're willing to sacrifice a little power to keep the ecosystem happy." ...

Cont'd
http://dsc.discovery.com/news/2008/08/26/river-power-energy.html

[The Croquist]

1. It sounds like a cool idea but...

I looked into installing a generator onto a dam I share with two other people. I still may do it but it will never be cost effective. There just isn't much power in water unless it's dropping a significant height (head). I wonder how far the river drops in one mile. I'm getting about a 7 foot drop in about 700 feet.

Dedicating a mile of the river is not a minor impact on the river although it's much less impact then a dam would have.
I wonder if silting and flooding will be an issue. Heavy storm runoff makes me nervous that my generator may end up down stream in pieces. Hopefully that won't happen to the polyvinylidene fluoride. One mile by 30 yards would make a hell of a mess.

If this works it might be possible to do this in large lakes and bays. The great lakes might be ideal for this if you can float them at or below sea level.

It sounds like it's worth experimenting with.