Lord Drayson launches Freevolt energy harvesting device

In the historical surroundings of the Faraday Theatre at the Royal Institution, the chairman and CEO of Drayson Technologies laid out his vision for the new device, which he hopes will help power the Internet of Things (IoT). Alongside Freevolt, Drayson also revealed its first commercial application – a system called CleanSpace that combines an air quality sensor with an app to measure and record pollution levels.

“Companies have been researching how to harvest energy from WiFi, cellular and broadcast networks for many years,” said Drayson. “But it is difficult, because there is only a small amount of energy to harvest and achieving the right level of rectifying efficiency has been the issue – up until now.”

Freevolt’s patented technology was developed by an international team from Drayson Technologies and Imperial College London. The device - about the size of a smartphone - uses a multi-band antenna in combination with an “ultra-efficient rectifier”, converting the alternating current to direct current. The third core component is a power management module that tracks the power, enhancing the efficiency of the energy collection.

“It’s a bit like a dog that’s picked up a strong scent and just will not let go of its target,” Drayson told the audience. “That maximises the power we can harvest, even though the RF energy is changing all the time.”

Though the amount of energy harvested by Freevolt is relatively minor, there are a host of low-energy connected devices that it could potentially power, including smoke alarms, building sensors, retail beacons, basic CCTV, and wearables. According to Drayson, the technology is also scalable, opening up the possibility of more advanced devices being powered in the future.

“The amount of energy that Freevolt can harvest is proportionate to the size of the harvesting antenna, and the number of harvesters we use,” he said.  “As we increase the size and number of harvesters – a bit like is done in a solar panel array – the amount of power we can harvest goes up.”

Drayson said Freevolt arrays could be used to panel the side of a house, or power an advertising display. Because they rely on radio waves rather than light, they don’t have to be orientated in a specific direction in order to function. This also means they can be hidden from sight for aesthetic purposes. 

“Unlike a solar panel that has to be on the outside to see the sun, these harvesters can be inside the brickwork,” said Drayson. ‘This is something we may well see in the future.”

CleanSpace will be the technology’s first real-world road test. Powered by Freevolt, a CleanSpace Tag measures carbon monoxide levels, feeding the information back to an accompanying app. The app uses this information in a variety of ways, displaying optimal routes for air quality, showing users the pollution they’ve been exposed to over a period of time, and rewarding users for making green journeys.

“Air pollution in London, like all major cities in the world, is a serious health problem,” said Drayson. “In certain cities it’s obvious – you can see it, you can smell it, you know it’s there. In cities like London and Paris, where it’s invisible, people are not so much aware of the problem.”

“But air pollution is killing millions of people across the world. It’s now recognised by the World Health Organisation (WHO) as the single biggest global health problem – more than HIV/AIDS and malaria combined.”

Partly inspired by Drayson’s own history of asthma growing up in London, the device promises to provide a platform from which air quality can ultimately be improved. It never requires charging, and delivers around the clock monitoring for up to five years.

“It’s constantly measuring air quality,” said Drayson. “It’s got on-board processing power, memory, a Bluetooth low-energy radio which enables it to communicate with a modern phone, to be then able to present the information to you and display it.”   

The tags will initially retail for £65 via Crowdfunder, where CleanSpace is aiming to raise £100,000 in funding before October 27. The price includes a £5 donation to one of three charity partners – EarthWatch, Sustrans or British Lung Foundation.