19-10-2017, 11:22 AM
The original meaning of the word "piezoelectric" implies "electricity of pressure", the generation of electric field from the applied pressure. Alternative energy will become increasingly important as fossil fuels deplete or environmental damage awakens consumer awareness. The search for a viable energy alternative will continue until these alternatives can address the dynamic demands of the power grid and storage constraints. Piezoelectric devices, used to collect the vibrational energy of roads and sidewalks due to traffic, can produce electrical energy that is predictable (according to traffic patterns) and can be stored locally.
Piezoelectric devices generate electrical energy through a piezoelectric crystal. The glass, placed about 5 centimeters below the surface of the asphalt, is slightly deformed when vehicles travel across the road, producing electric current. These devices have been implemented by the East Japan Railway Company (under the gates of the pedestrian subway station) and by Innowattech (under the roads in Israel). Innowattech has announced that these devices, if planted along a one kilometer stretch of road, could provide an average of 400 kW of power, enough to power 162 Western-U.S. households. These data suggest that piezoelectric energy collection is a clean and competitive alternative energy source. In response to these findings, in 2011, California State Assemblyman Mike Gatto proposed Assembly Bill 306 to develop this technology for Californian highways. However, it is unclear whether the data actually reflect the physical limitations of piezoelectric energy extraction.