A
rising trend in the green technology world is experimentation with power
generation not from biofuel, water, or even wind, but the movements of people
in their everyday life. This is called kinetic energy generation, and you may
have heard of it briefly in the past few years. For instance, there is a dance
floor which harnesses the movements of those above it to generate electricity.
In addition, Nokia recently introduced a phone that charges itself by
generating power from the vibrations of their user’s movements. Such electricity
generation techniques seem to hold the key to sustainable energy as fossil
fuels become harder to come by and consumers are looking for green
alternatives. Before making judgments, however, one must examine the whole
technology and its implications.
First
things first, how does this stuff work? In simple terms, a magnet bounces
around with some copper springs to produce electricity. In more scientific
terms, the kinetic energy generator works because of the Faraday principle. The
movement of the magnet causes a movement of its magnetic field which moves
electrons which are conducted by the copper wire into a battery. This is generally
how these generators work, but as it is a relatively new and open field,
producers of this technology are incredibly stingy with any real, solid, and thoroughly
explained information.
What we
do know about generating kinetic power, is that it’s all about long periods of repetitive,
constant motion. For instance, a biker, jogger, or walker who wears one of
these devices while exercising would create much greater amount of energy than
a baseball player who wears the device during a game. The repeating movements
for long time periods are more important than the strength of each motion.
Recently,
the Department of Defense recognized the military possibilities of this
technology for use in combat situations. Currently, soldiers lug twenty to
thirty pound batteries in their rucksacks to power their communications tools.
By adopting this kinetic energy generation techniques, soldiers could lose the
heavy batteries and replace them with smaller ones that charge constantly as
they move. This could increase mobility and energy reliability of troops. To
ensure fast development of this technology, the DOD invested nearly $10 million
their development.
Well,
if kinetic energy generators work for soldiers, they will surely work for
civilians in the US right? In most cases, the answer is no. Kinetic energy generators
rely on the movement of the wearer to create electricity. Most sedentary
Americans produce only energy to power a phone for 15 to 30 minutes. This means
that the technology is far from applicable to do anything more than briefly
extend phone life. The cost of this technology is also an issue. As there is no
possibility for municipal or government use of the energy, it would come down
to consumer action to popularize the product. Current models of kinetic energy
producing products sell for between $150 and $300, making it easier and cheaper
to simply charge devices at power outlets. The only thing a consumer really
gains from this product is a superficial (and largely false) sense of helping
the environment.
(1).jpg)
What about
the kinetic dance floor? Surely this technology could produce enough energy to
make a difference in energy usage. Each floor tile, about 30 inches square,
produces about 35 watts of energy in ideal conditions. Now imagine, perhaps, a
whole room in a busy New York City subway station, covered with these tiles on
the floor. There are 5000 tiles total and they operate at peak production 24
hours a day. Together, these tiles could produce 4200 kWh (kilowatt hours) of
electricity per day. This sounds like a lot of energy, however the average American
uses 250 kWh of electricity per day. This means that the entire system would
provide power for only 17 people if operating at maximum efficiency all the time
(both of which are basically impossible to achieve).
So
where do we go from here? Obviously, this technology only makes sense for the
most active of people and would provide energy for only the occasional charging
of an electronic device. The vast majority of Americans move too little and use
too much electricity for this technology to be feasible. Without nearly magical
improvements in efficiency, kinetic energy generators are and will stay
unpractical. Green energy pursuers should abandon this area, as it is a nice
theory, but an incredibly weak producer in practice.Sources
http://www.extremetech.com/extreme/161079-kinetic-energy-harvesting-everyday-human-activity-could-power-the-internet-of-things
