Wind turbines have come a long way, but there’s a big downside to them: they need to be big to truly be efficient. Well, that may soon change.

Forget strong winds or giant wind turbines. Scientists have now found a way to generate power from a gentle breeze, allowing urban areas with slower wind speeds to tap from this form of clean energy. The small wind harvester is the size of a water bottle and is made of copper, aluminum, and other parts, with a cost estimated at $10.

When exposed to winds with a speed as low as two meters per second, the device can produce a voltage of three volts and generate electricity power of up to 290 microwatts, the researchers note. That’s enough to power long-energy electronics, such as lights or commercial sensor devices, which are becoming growingly popular.

“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,” Yang Yaowen, one of the study’s researchers, said in a statement.

Yaowen, an engineer at the Nanyang Technological University in Singapore, said the device also serves as a potential alternative to smaller lithium-ion batteries. It would only need occasional maintenance and doesn’t use heavy metals, which are used extensively in the manufacturing of large windmills – such as lead, cadmium, and crystalline silicon.

Expanding wind energy

Just like a wind turbine, the device converts kinetic energy from the wind into electricity. It can be easily attached to a building or a bridge, for example. Vibrations are picked up by the device, which then produces electrical charges on sheets built within. While still early in the works, the researchers see a lot of potential behind it.

While it won’t exactly be used to power our homes anytime soon, the device can provide a lot of utility in specific situations. With a day’s worth of wind, the device can generate enough power to power sensor devices on intermittent mode for over a week, or a LED array for 24 hours, Hu Guobiao, a study co-author, said in a statement. The technology can help technicians who have to replace batteries in sensors along train or sewage tunnels, he added.

The researchers are now exploring ways to use the device to power multiple sensors, especially in areas that are difficult to access, such as high-rise buildings. After working on the device for around 10 years, they now hope to further improve it, allowing it to produce more power and store energy in rechargeable batteries. They estimate it will be on sale by 2025.

“Wind energy does not contaminate, it is inexhaustible and reduces the use of fossil fuels,” Yaoweng said. “Our invention has been shown to effectively harness this sustainable source of energy to charge batteries and light LEDs, demonstrating its potential as an energy generator to power the next generation of electronics, which are smaller in size and require less power.”

Globally, wind energy continues its stride. Wind electricity generation increased by 17% last year, reaching 273 TWh according to the International Energy Agency (IEA). It was the highest among all renewable power technologies. However, to get on track with a net-zero emissions scenario, it’s still necessary to raise average annual capacity additions to almost 250GW, more than double 2020’s record growth.

The study behind the device was published in the journal Mechanical Systems and Signal Processing.