Harvesting Energy From Vehicle Transportation On Highways Using Piezoelectric and Thermoelectric Technologies

For many years, the rate of energy consumption has been higher than the rate at which natural
resources are being generated. Green energy is a major solution to achieve a sustainable future
and mitigate carbon footprints. Today, the transport sector highly relies on fossil fuel, consumes
nearly one-quarter of the total energy in developed countries and represents a massive
environmental burden. Hence, the fate of future energy security does not solely lie in the
efficient use of existing green energies but also in the development of new energy sources.
Besides, with the rapid advancement of technology, the growing need of self-powered
autonomous electronic system, wireless sensors and portable devices became an considerable
issue nowadays. Piezoelectric and thermoelectric technologies have showed potential to harvest
energy in non-traditional ways. However, the recent application of these technologies revealed
that it is still at an embryonic stage and very few made use of the potential ambient energy
being wasted on highways using both technologies. This study is first to propose the design of
piezoelectric and thermoelectric energy harvesting systems to make use of the huge thermal
energy due to solar radiation and mechanical strain due to moving vehicles to generate
electricity. Both systems were built at an experimental scale model and tested, under Malaysian
conditions. The thermoelectric energy harvesting system produced a maximum average, output
power of 1.55 mW and open-circuit voltage of 348.5 mV at a temperature difference of 17.2
°C, over a period of 6h per day. The Piezoelectric generated a peak DC voltage of 9.83 V, under
normal stress of 235.04 kPa while experiencing a maximum vertical deformation of 1.44 mm.
The piezoelectric system could achieve a maximum output power of 0.2 mW, with only a single
wheel and deliver a consistent voltage of 9.8 V, as long as there are vehicles running on the
model. The power density of the proposed thermoelectric and piezoelectric energy harvesting
designs was 0.028 and 0.023 mW/cm3, respectively. The large-scale implementation was
estimated. The thermoelectric appeared to be slighly more cost-efficient in terms of levelized
cost of energy.