Thanks for your query.
Erik Baard wrote up an article titled "Capturing The Body's Energy For
Work On and Off Earth", detailing theories and facts about harvesting
the human body's power output:
"According to the Center for Space Power and Advanced Electronics
(http://spi.auburn.edu/), 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 theres not 100% capture. Body heat, for example,
can only be converted with 3% efficiency with current thermoelectric
The author goes on to detail ome of the most promising mechanisms for
passively converting human body functions into electricity.
The full article can be found here:
Also of interest, on May 13 2005 A Japanese research team was
reported to have developed a fuel cell that runs on blood.
This biological fuel cell uses glucose, a sugar in blood, with a
non-toxic substance that helps to draw electrons from glucose.
"The newly developed cell in the size of a tiny coin is able to
generate 0,2 milliwatts of electricity"
In order to utilze human energy you also have the various pedal power
inventions. One can bee found here:
"How much power can one human being create?
This is an opinion. I used to be a competitive swimmer, and for a
number of years, I worked out 6 hours a day, swimming approximately 13
miles. Yes, 13 miles a day. If you pedaled that hard for that long you
might be able to run one ordinary refrigerator for 24 hours. To make
any kind of significant contribution to your energy supply, you must
use the most efficient devices you possibly can. For example, a small
refrigerator designed to be powered by solar power would be much more
practical. A rule of thumb: if the device was designed to be powered
by batteries, even BIG batteries, you might be able to keep up with
If your electric bill shows KWH (kilowatt-hours), take the number,
multiply by 4 (assuming you can crank out 250 watts for an hour) and
that is how many hours you will have to be in the saddle to create the
same amount of power. Sorry, it can be depressing. The moral: Using
less power is as important, if not more important, than making more."