Scientists Develop A Wind Harvester That Can Generate Power From Light Breeze

As engineers and scientists worldwide are grinding their brains to develop existing green renewable energy generation or to find new ways to produce green energy, there is a wave of research and innovations worldwide. Riding on one such wave, scientists at Nanyang Technological University (NTU) invented a new device that can harness the wind, as gentle as a light breeze. Further, the new Wind Harvester can also divert and store the energy as electricity in a battery to power devices when it’s not windy outside.

The study paper has been published in the scientific peer-reviewed journal Mechanical Systems and Signal Processing.

Small, Durable, & Cheap

Each wind harvester is small, low-cost and measures just around 15 x 20 cm (6 x 8 in). Thanks to its small size, the device can easily be mounted on the sides of buildings and would be ideal for urban environments.

Even with a velocity as low as two meters per second (m/s), the device can produce a voltage of three volts and generate electrical power of up to 290 microwatts. The energy generated is enough to perform tasks, such as powering a commercial sensor device and also sending the data to a mobile phone or a computer.

In fact, in laboratory tests, it could power 40 LEDs consistently at a wind speed of 4 m/s. In another, it was used to power a sensor that wirelessly relayed room temperature data to a mobile phone.

The developers boast that the wind harvesters are also durable with low wear and tear, as they are made from a fibre epoxy, a highly durable polymer. In addition, the main energy-generating attachment that interacts with the wind is also made from inexpensive materials such as copper, aluminium foil, and Teflon. Expectedly, overall manufacturing may be cheap.

Mechanism

As the harvester gets exposed to wind, the device starts vibrating. It consists of a cantilevered beam attached to a middle plate made of layers that harness energy through the triboelectric effect, in which different materials become electrically charged as they separate, in this context caused by vibrations from the wind. The vibrations cause the plate to approach and depart from the stopper. This causes charges to be formed on the film, and an electrical current is formed as they flow from the aluminium foil to the copper film.

It’s not the first time that this triboelectric technology is used to generate electricity. For instance, this type of triboelectric technology has also been deployed in other advanced wind harvesters, such as wearable devices that generate energy from the wind as you walk.

What Next?

The team is continuing work to improve the performance of the device and is filing a patent as they pursue the commercialization of the technology. The research will also focus on experimenting with different materials to improve the output power.

“As a renewable and clean energy source, wind power generation has attracted extensive research attention,” said Professor Yang Yaowen, who led the research. “Our research aims to tackle the lack of a small-scale energy harvester for more targeted functions, such as to power smaller sensors and electronic devices.”

Further, the invention has the potential to replace batteries in powering light-emitting diode (LED) lights and structural health monitoring sensors. Those are used on urban structures, such as bridges and skyscrapers, to monitor their structural health, alerting engineers to issues such as instabilities or physical damage.

“The device we developed also serves as a potential alternative to smaller lithium-ion batteries, as our wind harvester is self-sufficient and would only require occasional maintenance, and does not use heavy metals, which if not disposed of properly, could cause environmental problems,” he added.

While many questions will surround the new invention, it’s a welcome technology.