Dual electromagnetic energy harvesting technology for sustainable transportation systems

Safety and energy resources are two important necessities of a sustainable transportation. Energy harvesting from roadways has a potential to impact both requirements. In this study, the Hybrid electromagnetic energy harvesting prototype is introduced. The prototype consists of two mechanisms, linear generator and rack-pinion to generate the electrical power. The experimental tests and analytical models were conducted to examine the performance of the prototype. The prototype was designed to perform as a speed bump. In the experimental tests, the traffic conditions were simulated to provide better insight of the prototype's performance in real condition. The root mean square of the power outputs was measured, which was 1.2 W and 80 mW for the rack-pinion and linear generatormechanisms, respectively. According to the small scale of the prototype in comparison with real size, the results showed a promising technology to generate substantial electrical power in the field. The equivalent stiffness of the prototype is measured by experimental test which is 140,657 N/m. The analytical and experimental results show an agreement in influential factors for generating power; magnetic flux and relative movement for linear generator mechanism and vertical velocity and gearbox ratio effects for the Rack-pinion mechanism. In addition, the feasibility study showed that the prototype was applicable technology in roadways. The ease of installation, limited effects of the prototype on roadway performance and maintenance procedure make it an inevitable candidate for energy harvesting in roadways. However, it must be noted that the technology is still in its beginning stage and it must be developed in different aspects including generating power ability, endurance and cost-efficiency.