Researchers from the Nanyang Technological University (NTU) of Singapore published a paper in the Mechanical Systems and Signal Processing journal, presenting a device they developed which can transform even the slightest breeze into energy.
The team, led by Professor Yang Yaowen, structural engineer and Associate Chair of the NTU School of Civil and Environmental Engineering (CEE), has developed a low-cost device that can harness energy from wind as gentle as a light breeze and store it as electricity.
As a renewable and clean energy source, wind power generation has attracted extensive research attention. 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.Professor Yang Yaowen, structural engineer and Associate Chair at NTU School of CEE
The ‘wind harvester’ can generate electricity with a power of up to 290 microwatts and produce a voltage of 3 volts when exposed to winds with a velocity as low as merely 2 metres per second. The generated electricity is enough for powering a commercial sensor device, as well as sending the data to a mobile phone or computer.
The light and durable device, called a wind harvester, also diverts any electricity that is not in use to a battery, where it can be stored to power devices in the absence of wind. The scientists say their invention has the potential to replace batteries in powering light emitting diode (LED) lights and structural health monitoring sensors, which 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.
Due to the dynamic design of its structure, when the harvester is exposed to wind flow, it begins to vibrate, causing its plate to approach to 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.
Measuring only 15 centimetres by 20 centimetres, the scientists say the device can easily be mounted on the sides of buildings and would be ideal for urban environments, such as Singaporean suburbs, where average wind speeds are less than 2.5 m/s, outside of thunderstorms.
“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,” said Professor Yang Yaowen.
The device was developed to harness efficient wind energy at low cost and with low wear and tear. Its body is made of fibre epoxy, a highly durable polymer, with the main attachment that interacts with the wind and is made of inexpensive materials, such as copper, aluminium foil, and polytetrafluoroethylene, a durable polymer that is also known as Teflon.