Investigating the efficiency of piezoelectric wind energy harvesting in leaf-stalk structures

In this paper, piezoelectric wind energy harvesting with leaf stalk structures is classified and the performance of each structure with different configurations is investigated. In this research, the main purpose is comparing these harvesters in terms of their structures and determining the best configuration for each environment. In other researches, energy harvesting systems have also been investigated based on the type of fluid-structure interaction or type of piezoelectric materials; however, this study investigated leaf-stalk structures in which wind energy has been the main source of energy harvesting. Although the electrical power harvested from wind energy by piezoelectric materials is by no means comparable to the power of wind turbines, these harvesters are very low-cost, small, silent, and clean and used as a replacement for batteries that become chemical waste after use. In large numbers, they can be used for low-power consumption in commercial, sports or leisure centers. By examining the design parameters that improve the performance of leaf-stalk structure, it is found that in addition to load resistance and wind speed range, leaf and stalk geometry, their configuration, and distance between two systems and the presence or absence of veins affect the frequency of the flutter and consequently the performance of the energy harvesting system. In general, among different geometric shapes, triangle leaves have had the best performance. On the other hand, if the support base is jointed, it also has a positive effect on the performance of the system. Leaves with veins produce more output power than leaves without veins. Among the leaves with veins, the Pinant leaves will increase the efficiency of the system. Due to the wind speed constraints, the dimensions, and costs, one cannot determine the best system, but the best one can be identified for the specific conditions.