There's a way to harvest energy from radio waves

There’s a way for us to harvest unused radio frequency waves to power up low-consumption electronic devices such as wearables and various beacons, the media have reported on Thursday.

The new and patented method, called Freevolt, was unveiled by Lord Paul Drayson, the former minister for science and chief executive of Drayson Technologies, at The Royal Institution in London.

Lord Drayson said energy from Wi-Fi, cellular and broadband networks has always been interesting to researchers, but they could never put it to good use as it can only provide a small amount of energy. However, Freevolt harvests energy from multiple radio frequency sources at different frequencies and at almost any orientation at the same time, increasing the amount of energy that Freevolt can produce.

"It is the nature of broadcast transmissions that, when you broadcast, only some of the energy is received and used. The energy that is not received goes to waste. It's only nanowatts of energy, but the energy is everywhere," said Lord Drayson.

"What we're doing is using that fact to power very small low-energy devices. The radio frequency transmissions come from wireless networks, and as our hunger for information goes up, the amount of data that we want to transmit is going up exponentially, and therefore this is growing all the time."

The first commercial application of Freevolt technology is the CleanSpace Tag air sensor, which monitors air pollution (carbon monoxide) and feeds this data back to a smartphone app, allowing users to see exactly what they are breathing, wherever they are.