In recent years, we have become familiar with the concept of energy vampires: small devices around the house like phone chargers that steadily use up energy a little at a time. We’ve all been encouraged to avoid wasting energy in this way by unplugging these things.
More recently, researchers have started looking at opportunities for actually harvesting energy that is otherwise wasted. Things that produce heat, vibrations, radio and microwaves are all around us and all that emitted energy generally serves no purpose. Emerging technologies for scavenging waste energy could change all that.
Thermoelectric devices can convert waste heat into electricity and newer versions can operate on very little heat. Electronic devices could derive power from the vibrations from user’s footsteps. Tapping into low-level energy sources could in principle replace batteries in a variety of modern devices. Tiny sensors, processors and biomedical devices are all candidates for scavenged power. Sensors that don’t rely on depletable energy sources offer valuable reliability and flexibility. Electronic devices of all sorts could even derive some of their power from their own excess heat. On a larger scale, significant heat sources such as hot parking lot pavements and tailpipe heat could be exploited to great effect. Making use of ambient energy is likely to become increasingly common.
Most of the research into energy sources focuses on creating large amounts of energy because we are a civilization that uses megawatts and gigawatts of power. However exploiting ambient energy sources and shaving microwatts and milliwatts here and there from our power needs can add up to a lot of savings.
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In a Host of Small Sources, Scientists See Energy Windfall
Photo, posted May 10, 2009, courtesy of Alan D. via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio.