Can we generate power from moving crowds?

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Offline thedoc

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Can we generate power from moving crowds?
« on: 14/02/2013 19:31:14 »
A group of US and Chinese researchers have developed a generator that can convert footsteps into electrical power...

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« Last Edit: 14/02/2013 19:31:14 by _system »

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Offline techmind

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Re: Can we generate power from moving crowds?
« Reply #1 on: 14/03/2013 23:58:44 »
But the amount of energy you get out is pretty miniscule compared to the time, effort and energy required to make, install, and maintain any such system. And of course this will make it a little bit more tiresome for the individuals to walk about. There is never any real energy-payback with such systems. "Energy harvesting" is rarely ever really about "energy saving" - it's only real value is when no other source of energy is viable (eg in the middle of nowhere, impractical to have someone changing batteries on a regular basis etc etc).

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Wang and his team produced a nanogenerator smaller than a human palm  which generated an instantaneous output power of 1.2 W. While this may not sound like much, it is enough power to light a bank of 600 coloured LEDs with a single human step!

What does "instantaneous" mean in the context of a footstep? Is that a split second each time a foot hits the ground ... a pretty low duty-cycle for walking! Sub 5%? So maybe equivalent to 50mW continuous? Quite possibly less. About 0.02p-worth of (mains) electricity per day from continuous 24h-walking.
« Last Edit: 15/03/2013 00:07:25 by techmind »
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