Piezoelectric Hydropower System May Power 20-40% of Pennsylvania Town
by Matthew McDermott, Brooklyn, NY on 09. 2.08
photo: Casey West
Hydroelectric power generally conjures up images of massive dams creating reservoirs behind them, submerging trees and sometimes even towns. While technically a form of renewable energy (and generally included by most countries when they tout how much of their electricity is generated from renewable sources), large scale hydro isn’t exactly environmentally friendly. A better (if not perfect) hydro option is run-of-river hydro, which while still often employing some form of reservoir can be done on a less intrusive scale.
Another No-Dam Hydropower Method to be Tested
An intriguing third hydropower option is being developed in the town of Vandergrift, Pennsylvania in the Kiskiminetas River which the town hopes will generate 20-40% of its electricity. Our colleagues over at Discovery News have the complete story, but here’s that requisite bit to lure you in:
[The] sustainable power [Vandergrift is developing] 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.The exact details about how dense the grid would be, how long the PVDF strips will be, or even when the grid would be laid down, are still being worked out. But whatever the final plans are, the researchers claim they will maintain the health and appearance of the Kiski, which is used for fishing, canoe trips and other recreational activities.
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It's a laudable goal to look for available renewable energy sources to increase the town's electricity self-sufficiency. But I think that using PVDF to get there is going to be very disappointing. The piezoelectric effect is among the least scalable energy conversion method there is. It works fine on tiny scales, but is awful when you try to size it up to the number of watts as would certainly be required to run multiple homes. It can barely break 100 watts, never mind a more reasonable 100,000 watts.
An alternative suggestion...
Why not flow the water from the main lines of the city through generator at strategic points. Most houses already use regulators to reduce the pressure from the main lines to the home lines. The only downside would be fire hydrants and industrial uses that require higher flow.
Maybe do it on individual houses?
Just a thought I have no idea how much pressure is actually in the average mainline.
Does anyone know better?