Unwasted Energy

摘要

Physicists seek ways to harvest "junk" energy in the environment. From the vibrations filling the air when jets take off to the waves generated by radio and television transmitters, our environment is full of largely wasted energy. Now, researchers are seeking ways to capture that energy and turn it into useful sources of electricity. One of the challenges is that communications devices transmit energy at different frequency ranges, so whatever devices are used to harvest this energy needs to hone in on the right band in order to capture the energy. (Currently, scavenging devices can work in ranges from FM radio to radar.) Then the energy needs to be converted from AC to DC, and stored in capacitors and batteries.