Piezo-electricity can theoretically be applied to large structures like bridges to generate electricity from traffic, but it does not provide free energy. The energy harvested from piezoelectric materials comes from the additional fuel consumed by vehicles due to the deformation caused by their weight. Similar applications, such as piezo inserts in shoes, also rely on energy derived from the food consumed by individuals. While the technology could be used to capture energy from pedestrians on busy streets, the overall energy gain is limited by the energy input required for movement. Therefore, while feasible, piezo-electric applications in large structures may not be a practical energy solution.
