Over the years, various researchers have developed systems in which the weight transferred through cars' wheels onto the road – or through pedestrians' feet onto the sidewalk – is used to generate electricity. These systems utilize piezoelectric materials, which convert mechanical stress into an electrical current. Such materials may be effective, but they're also too expensive for use in many parts of the world. That's why Mexican entrepreneur Héctor Ricardo Macías Hernández created his own rather ingenious alternative.
Read the full article: Low-cost system uses passing vehicles to generate electricity