Energy harvesting by piezo-tires and their life cycle assessment

Piezoelectric materials can convert mechanical energy into electrical energy. These materials have the potential to provide reliable and cost-effective replacements of energy sources. It can ultimately have the potential to reduce fuel costs in vehicles. The use of piezoelectric materials in pneumatic tires enables capturing the waste energy of cars because of deformations in tires. An experimental setup was designed and constructed to simulate the movement and pressure inside the tire of a car. Piezoelectric elements were attached to the external perimeter of the model tire. Based on the experimental results, this method produced 2.31 W for 56 piezo-elements comparable to 2.3 W for 160 piezo-elements found in the literature. The results showed that placing piezoelectric elements on the outer surface of tires has a higher potential in harvesting the waste energy in vehicle tires. The harvested energy has a direct relation with the compressive stress under the contact patch of the tire. In addition, the harvested energy increases by increasing the velocity and applied weight. In addition to the experimental study, the environmental effects of harvesting waste mechanical energy in tires by using piezoelectric materials bonded to tires were evaluated through a life cycle assessment. The results showed that in addition to harvesting some of the waste energy in cars, it contributes a slightly higher environmental load than ordinary tires. Further evaluation of the technology is required to measure the durability and the lifetime of piezoelectric materials.