A piezoelectric generator in public spaces captures energy from communal activities through a process called piezoelectric energy harvesting. Piezoelectric materials have the unique property of generating an electric charge when mechanical stress or pressure is applied to them. This phenomenon is called the piezoelectric effect. When people engage in activities that involve movement or apply pressure to certain surfaces, these actions can cause mechanical deformation in the piezoelectric material, leading to the generation of electric charges.
Here's how a piezoelectric generator in public spaces works to capture energy:
Placement of Piezoelectric Materials: Piezoelectric materials are strategically placed in areas where there is frequent foot traffic or other types of mechanical interaction. Common examples include sidewalks, floors, stairs, or even furniture like benches. The goal is to harness the mechanical energy generated by people's movements.
Mechanical Deformation: As people walk, run, or engage in other activities on the surface containing piezoelectric materials, they apply mechanical force or pressure. This force causes the piezoelectric materials to deform slightly, creating a displacement of charged particles within the material.
Generation of Electric Charges: The mechanical deformation leads to a separation of positive and negative charges within the piezoelectric material. This separation of charges generates an electric voltage across the material. The more force applied, the greater the deformation and the higher the voltage produced.
Energy Harvesting Circuit: The generated electric voltage is relatively small and AC (alternating current) in nature. To make this energy usable, it needs to be converted into a form that can be stored or used to power devices. An energy harvesting circuit is used to convert the AC voltage into DC (direct current) voltage, which can then be stored in batteries or capacitors for later use.
Energy Storage or Direct Use: The harvested energy can be used to power low-energy devices directly or stored for later use. In public spaces, this energy can be used to power lighting, small electronics, charging stations, or even be fed back into the grid if the generated energy is substantial.
It's important to note that while piezoelectric generators are efficient at capturing energy from mechanical interactions, the amount of energy generated from individual actions is relatively small. However, in highly trafficked public spaces with a large number of people, the cumulative effect of many interactions can result in a significant amount of harvested energy over time.
Piezoelectric energy harvesting is a form of sustainable and "green" energy capture that takes advantage of existing activities in public spaces to generate electricity without additional environmental impact.