An experimental study on piezoelectric energy harvesting from palm tree induced by wind

The aim of this study is to generate energy from the movement of a palm tree branch that has the potential to power wireless sensor nodes by means of wind energy. An experimental investigation of a piezoelectric based energy harvester on a Bismarck (Bismarckia nobilis) palm tree was performed. The branch was placed in the test section of a wind tunnel that provided the airflow speed in a controlled environment. The energy was harvested from a palm tree that was clamped at the end of the stem and induced to vibrate at ambient wind speeds. The results showed that there is a linear relationship between the wind speed and voltage generated; as the wind speed increased, the power output increased. The voltage produced under different wind speeds (2-7 m s(-1)) with various load resistors were tested to determine the maximum power output. A maximum power output of 0.157 mW was produced when using an optimal load of 1 Omega M, which corresponded to a power density of about 393 mW m(-2) at airflow speed of 7 m s(-1). It was also observed that the voltage produced at various flow speeds was enough to generate high levels of power for powering small sensors.