UC Merced

Massive dissipated kinetic energy of roadway traffic is a sustainable energy source that can be harvested via piezoelectric effect. This approach provides a robust and reliable solution of roadway power generation. However, to achieve high energy density remains challenging. This thesis focuses on the development of a high density piezoelectric energy harvesting system from roadway traffic, which reaches an energy density as high as 15.37 J/(m.pass.lane) in drive tests. The high energy density is achieved by incorporating a compression-to-compression force amplification mechanism which amplifies the harvested energy by a factor of 100, as well as an optimized system configuration to take full advantage of dynamic load from vehicles. To the best of our knowledge, the scalable prototype system has achieved the highest energy density, which holds the great potential to enable self- powered smart road on a large scale. Based on the drive test results, implementation of this technology in one lane of 1609.34 m can generate at least electric energy of 7.22 × 10^4 kWh in one year.In this dissertation, the details of proposed piezoelectric energy harvesting technology are presented, including mathematical modeling and analysis, optimization of design parameters, mechanical design at all levels, lab test method and results, road implementation and drive test results. The chapters are organized as follows. Chapter 1 reviews recent developments of piezoelectric energy harvesting, including materials, configurations, and performances, followed by the discussion on the challenges and trends. Chapter 2 introduces the mathematical modeling of proposed design idea, derives the equations of motion for theoretical exploration. Chapter 3 demonstrates the procedure of dynamic analysis for this modeling, and presents simulation results of a selected design. Chapter 4 explains how we con- ducted parameters optimization for high energy density based on the mathematical modeling, afterwards, illustrates the mechanical design for the realization of an aggressive selected design and its laboratory validation. Chapter 5 introduces the vertical packaging of PEHUs, piezoelectric energy harvesting tower, including mechanical design, quasi-static compression test results, battery charging test results. Chapter 6 shows the system design for the implementation on road from both the electrical and mechanical perspectives. The drive test results based on a prototype system on the campus of UC Merced are presented. Chapter 7 discusses the optimal designs for the traffic of heavy truck for future exploration. Chapter 8 summarizes the thesis and discusses future directions.