Ultra-High Power Density Roadway Piezoelectric Energy Harvesting System

Advanced piezoelectric technologies can generate electricity from otherwise untapped mechanical energy resources. Piezoelectric technologies provide the opportunity to harvest energy where stress or vibration is generated and have the advantages of high-power density, simplicity, and scalability for a variety of applications. Heavy traffic of ground vehicles and pedestrians on highways, streets, and sidewalks provides considerable mechanical energy. Harvesting this energy can increase distributed renewable energy capacity. However, there is a lack of the comprehensive understanding of piezoelectric energy harvesting systems and their potential. This project takes an integrated multi-disciplinary approach involving mechanical, electrical, engineering, civil, and automobile engineering, material science, and physics to develop technologies for harvesting high-density piezoelectric energy. 

The goals of the project were to design a piezoelectric energy harvesting system to achieve an electrical energy density of 333 watts per square foot with the cost of the system reduced to $9,010 per kilowatt and a lifetime of up to 20 years. The project team developed and demonstrated an innovative piezoelectric device for harvesting energy from highway traffic. The results were supported through numerical simulations, experimental investigations, and road tests. Based on the laboratory evaluations and road tests, the application of the piezoelectric energy harvesting system in one lane of a one-mile-long roadway has the potential to generate 72,800 kilowatt-hours of energy per year. For heavy trucks, the annual electric energy over one mile of a one-lane highway can be as high as 907,873 kilowatt-hours, which is equivalent to a reduction of 300 metric tons of carbon dioxide. California has 386,604 lane miles. Outfitting all these lane miles with piezoelectric energy harvesting devices would yield a carbon dioxide reduction of 115 million metric tons annually in California. Other potential applications include warehouses, seaports, aircraft runways, and railroads.