Vibration Harvesting — Feast or Famine?

They are absolutely no use for 'power' generation.
They may be handy for generating v small amounts of power for instrumentationor such like in places where no convenient power source is present. So that's somewhere dark with no mains supply that's inaccessible for battery changes.
Del

no idea about the green aspects

the ability to add remote sensors with out having to run power, makes it handy to acquire more data points...

I like the idea of embedding them in highways to power the streetlights. Maybe they could be put into entertainment venues and shopping malls to offset some of the energy costs. If they become efficient, durable, and inexpensive, I think they could actually have quite an impact on the energy scene.

See comment #1

Yes, I read comment #1. Much as it pains me to disagree with the friendly feline, I think vibration harvesting has great promise -- providing, as I stipulated, that the devices become efficient, cheap, and rugged.

Piezoelectric devices aren't new or very efficient

The energy harvesting application is new. The underlying technology is not limited to piezoelectrics. And I have great faith in the engineering community's ability to continually improve technology; that's what engineering is all about!

The have a look here Optimism is fine, but there is no free lunch

No free lunch -- but plenty of wasted energy to be harvested, and plenty of brain-power being spent on research. I respect the opinions presented in the previous discussion, but I don't share the pessimism. Solar energy was totally impractical ten years ago, too, but solar cells have become so much more durable and efficient, they now make sense. Farmers abandoned their old windmills when electricity came in; now they're renting out their land to wind farms. I disagree with you, Garthh -- but I'm not betting money on it, either.

Reality is neither pessimistic or optimistic

It makes more sense to save the energy before it's wasted

there's plenty of good engineering to be done to increase efficiency & reduce waste.

solar & wind are heavily subsidized, the practicality is debatable

Interesting article from Science Daily:

"...new Energy Harvesting Network being launched could mean virtually unlimited power supplies..."

http://www.sciencedaily.com/releases/2010/02/100225084634.htm

Also see several other articles on the same topic.

once again just eliminating a few batteries from wireless sensor networks