Statistic No.1 - from Space magazine article- "People Power: Capturing The Body's Energy For Work On and Off Earth" by Erik Baard:
"According to the Center for Space Power and Advanced Electronics, a NASA commercial center in Alabama, the human body is on average 15% fat, capable of producing 11,000 watt hours. When the average Joe eats his daily bread, he takes in 3,300 watt hours. The charge rate is about 7kW if the waiter starts pushing you out the door after a half hour lunch, according to the Center. "Clearly the amount of energy consumed by an individual is sufficient to provide power for electronic devices if a suitable method can be found to convert a small fraction of that energy to electricity," the Center concludes in a report on the subject.
Broken into usable terms, waiting to be harvested are 81 watts from a sleeping person, 128 from a soldier standing at ease, 163 from a walking person, 407 from a briskly walking person, 1,048 from a long-distance runner, and 1,630 from a sprinter, according to the center. But of course there’s not 100% capture. Body heat, for example, can only be converted with 3% efficiency with current thermoelectric materials."
Statistic No.2 - (www.scienceshareware.com)
Many people, doing physical activities are concerned with the amount of calories they burn...
Electrical energy is measured in different terms so how do one Converts energy data of Watts to Calories burned?
1.Convert Watt-Hours to Watt-Seconds (Joules) 2.Then convert Joules to Calories 3.Then adjust Calories with human body efficiency factor
So for this example let's assume that you provide pedal power to a 100 Watt television for one hour. Since one Joule is equal to one Watts X Seconds you perform dimensional analysis and get:
100Watt-hours X (3600 seconds / 1 Hour) = 360,000 J
Now use the conversion factor: 1 cal = 4.184 J to convert Joules to Calories
360,000 J / 4.184 = 86,042 Calories
When you look at the label of Oreo cookies or other food items at teh store, the term "Calories" is realy (kili-Calories). So you divide by 1000 to get 86 Calories.
Assuming that your body is about 25% efficient when cycling you divide by .25 the Calories burned running a 100 Watt Television for 1 hour = 86 / 0.25 = 344 which is about equivalent to one piece of PIZZA!
Statistic No.3 - Piezoelectric energy efficiency: (http://www.blackstone-ney.com/04.TPmagvs_piezo.php)
Piezoelectric transducers are extremely efficient due to the direct conversion of electrical to mechanical energy in a single step. Direct application of the power to the piezoelectrically active ceramic causes it to change shape and create the sound wave. Energy losses in the ceramic due to internal friction and heat are typically less than 5%. This means that up to 95% of the power delivered to the transducer is used to do cleaning. Modern ultrasonic generators used to drive piezoelectric transducers are generally over 75% efficient making the overall system efficiency 70% or higher.
Statistic No.4 - (http://www.los-gatos.ca.us/davidbu/pedgen.html)
Pedal generator: For immediate electrical use, cigarette lighter outlets provided direct access to the generator output. I even had a small 12v toaster oven, and pedaled bread to toast more than once. For electricity storage I would charge a 12v 100Ah fork-lift battery. I could approximate the output of a small 10 amp battery charger.