A piezoelectric generator in public transportation systems captures kinetic energy through a phenomenon called the piezoelectric effect. The piezoelectric effect is a property of certain materials (such as certain crystals or ceramics) that generate an electric charge in response to mechanical stress or deformation. This means that when these materials are subjected to mechanical pressure, vibration, or movement, they produce an electric charge.
In the context of public transportation systems, piezoelectric generators are often installed in areas where there is frequent mechanical stress or vibration, such as:
Under Floors: Piezoelectric materials can be embedded in the flooring of buses, trains, or subway cars. When the vehicle moves, accelerates, or decelerates, the vibrations and mechanical stress caused by the movement result in the deformation of the piezoelectric materials. This deformation generates electric charges, which can be harvested and stored.
Suspension Systems: Piezoelectric generators can also be integrated into the suspension systems of vehicles. As the vehicle travels over uneven roads or tracks, the suspension absorbs shocks and vibrations. These movements can be converted into electrical energy using piezoelectric materials.
Braking Systems: Braking and deceleration involve mechanical stress on the braking components. Piezoelectric generators can be placed strategically near braking systems to capture the energy produced during the braking process.
Doors and Entryways: Public transportation vehicles have doors that open and close frequently. The mechanical motion of these doors can be utilized to generate electric charges using piezoelectric materials.
Passenger Seating: Piezoelectric materials could also be incorporated into seating structures. When passengers sit down or shift their weight during travel, the resulting mechanical stress can be harnessed to generate energy.
Once the piezoelectric generators capture the mechanical energy and convert it into electrical energy, this energy needs to be properly managed and stored. The generated electricity is typically in the form of small voltage and current outputs. This harvested energy can then be used to power various systems within the transportation vehicle, such as lighting, communication devices, climate control, or even fed back into the vehicle's power grid to reduce overall energy consumption.
It's important to note that while piezoelectric generators can capture energy from vibrations and mechanical stress, the amount of energy generated might not be very large. However, when implemented across a fleet of vehicles or combined with other energy harvesting technologies, piezoelectric systems can contribute to overall energy efficiency and sustainability in public transportation systems.