This paper proposes an electromagnetic device equipped with a double magnet design that can harvest energy from natural, low-speed wind (global average of 3.28 m/s). The tip prism activated by aeroelastic galloping is equipped with four magnets arranged in an opposing-pole formation, producing a concentrated magnetic-flux gradient through the coil without requiring mechanical links. A prototype device (110 × 105 × 25 mm3) is tested in a wind tunnel and analyzed by numerical simulation. The device begins to provide power at a wind speed of 1.5 m/s, producing an average electrical power output of 1.41 mW at 4 m/s. This configuration is notable for its extreme simplicity.

This study aims to develop a device for harvesting electrical energy from low-speed natural wind. Four linear Halbach arrays are adopted to design a high-performance galloping harvester with the advantage of high durability and efficiency at low-frequency vibrations. The results of magnetic field analysis reveal that there are optimal sizes of the main and transit magnets of the Halbach arrays and coil to obtain the maximum magnetic flux density normal to the coil. The experimental and simulation results show that the electrical external load resistance significantly affects the vibration amplitude and the galloping onset velocity of the harvester. The results also reveal that the performance of the original design using the quadruple Halbach array was lower than that of the existing harvester because of the heavy magnet mass embedded in the tip prism. The modified design, reducing mass, improved the performance by four times compared to the original design.