Electricity generated from sound? It may not be as far-fetched as it sounds, (no pun intended). Scientists in Korea using nanogenerators have done just that. These generators are built upon piezoelectric ZnO nanowires which turn vibrational energy into electrical energy. How-ever piezoelectric research can be traced back to 1880 by the brothers Pierre Curie and Jacques Curie, inventions using the technology came during World War 1 with sonar and ceramic phonograph cartridges.
Theoretically you could power your cell phone, car or lights using this nano technology. At the moment they are only getting about 50 millivolts from the system. Though you may not get enough sound energy to charge a phone completely, at least you can extend battery life.
"Just as speakers transform electric signals into sound, the opposite process -- of turning sound into a source of electrical power -- is possible," says Young Jun Park and Sang-Woo Kim authors of "Sound-driven power generation" published in Advanced Materials.
Possible candidate for renewable energy below:
Eavesdropper
Image of mcontent from: http://onlinelibrary.wiley.com/doi/10.1002/adma.201001169/abstract
image of car from: www.geardiary.com
image of car from: www.geardiary.com