Why aren't we harvesting energy production from Americans WALKING?

[Blackhatjack]

A few general statistics: Average weight of American Man 175-191 lbs, Average weight of American Woman 125-150 lbs, Average number of steps American takes in a day 7,000-10,000 per day

So assume each step taken is a weight shift of the average weight, and you should have an event that would produce harvestable energy.

For example, 175 lbs X 7,000 steps with complete weight shift = 1,225,000 lbs shifted per day PER PERSON

Are we missing something here? Assume that the steps only result in a 50% shift of weight and you still get 612,500 lbs shifted per day PER PERSON

There are companies already attempting to exploit this potentially energy generating activity. For example:
Rubber film that generates power from walking breathing

"Princeton University engineers have come up with a rubber film that harvests kinetic energy. But it's not just another piezoelectric film. The team has been able to combine silicone and naonoribbons of lead zirconate titanate (PZT). PZT is the most efficient of kinetic-energy harvesting materials, converting as much as 80% of mechanical energy into electrical energy. By being the first team to successfully embed it into silicone, the Princeton engineers have opened up a whole slew of possibilities for where piezoelectric materials can be used - from inside the body to the soles of our shoes."
http://www.treehugger.com/files/2010/01/new-rubber-film-could-harvest-energy-from-breathing-walking-to-power-gadgets.php

Sidewalk slabs convert kinetic energy into electricity

"When each rubber slab from UK-based Pavegen Systems (discovered on Springwise) gets depressed, each time it converts the kinetic energy used into electricity. This is then stored in the slab. Specifically, 5 percent of the energy harvested is used to make the slab's LED glow, making it clear to users that their energy has been captured. The rest can be used to power pedestrian lighting, information displays and many other applications."
http://planetgreen.discovery.com/tech-transport/reasons-footsteps-generate-energy.html

Sure the amounts of energy being generated may be small and useful for recharging small energy requirement gadgets today, but every amount generated could help replace the use of non-rechargeable batteries --which are inefficient and a threat to the environment.

[Oregone]

1. Im not a battery

[asdjrocky]

2. Are too.

[gcomeau]

3. Americans walk? -nt

[Nikki Stone1]

5. +1

:D

[nemo137]

4. Because we have enough trouble getting sidewalks repaired

much less converted into energy-capturers?

[4lbs]

6. I believe I saw a news segment about that invention. They wanted to put them into malls, so all

that foot traffic could be used to partially power the malls.

[Spike89]

7. What's the payoff equation?

Typically, the problem with micro-transactions isn't that they are worthless, but that the overhead makes them impractical. For instance, if takes considerable energy to contruct the rubber power-generating slab, along the order of 5X the annual generation of energy, then the slabs are "free power" in the 6th year. However, if the practical lifespan of the slab at that rate of use is 4 years, there is a net loss/waste of energy.

Another problem with so many of the new green technologies is the efficiency curve. Ironically, rapid advances in technology make it more difficult to implement current solutions. Here's an example of this...say solar panels capable of powering your entire home are currently about 10% efficient (pay for their energy cost in 10 years) and lets posit they have a 20 year lifespan. Well, everyone should run out and convert. However, we hear that MIT, NASA, or even some dude in a garage is on the verge of announcing a 25% efficient solar panel with a 20 year life. In that case, the people that bought early are paying 2.5X as much and "wasting" that much energy. Overall, the people that wait one year, generating no energy at all, will still end up using less net energy well before the 2nd year is over.

Of course, if we all wait, then there is no money for the 10% manufacturer and probably no money to invest in the development of the 25% models, or eventually the 30+% efficient ones. This is why government has a much needed role in funding research to kickstart the process and artificially jump us to a level that is attractive enough that it won't become obsolete before it actually pays off.

[Blackhatjack]

8. That is why simple low cost technology should be embraced...

The concept has been proved. It is being overlooked because the annual savings are not in the range that would make for a substantial profit per unit.

I agree with you about advances in technology outstripping products with a 20 year useful life on the market today.

That is where the low cost technology plays an important role.

We don't necessarily need technological advances that will have useful lives of 10-20 years. We need devices that generate plus side energy savings that last anywhere from 90 days to 1 year, that can be purchased as easily as lightbulbs.

If the cost of the devices is lower than the cost of existing technology over the same time curve, people will buy it. And the savings on landfill alternatives will make these products worthy of government subsidization.