The Internet of Things is a growing phenomenon. Everyday objects from appliances to pet collars are increasingly becoming “smart,” powered by software, sensors, and various technologies to communicate with users and other devices via the internet. The business forecast for this so-called physical web is impressive: one study estimates more than a 10% growth rate in the next five years, attaining a market value of $1.39 billion by 2026. However, IoT has a significant hurdle to overcome: power.
Larger appliances with fixed physical locations often have dedicated electrical connections. However, many IoT devices are smaller mobile technologies that rely on batteries rather than a dedicated energy source. One study suggests that by 2025, there will be 41.6 billion IoT devices, including heart monitors or agricultural sensors for which wired power is impractical.
Enter the smart power company WiGL (Wireless-electric Grid Local Air Networks). Pronounced “wiggle,” its namesake technology is a form of wireless and touchless power. Wireless power is relatively common now that many smartphones, watches, and rechargeable toothbrushes allow surface charging rather than cable charging. However, touchless power offers an entirely different capability: delivering electricity through the air. Imagine your phone, watch, or toothbrush—or any equipped mobile or battery-powered device—deriving electricity all the time, without the need to be connected to a power cable or docking station ever again. While intriguing, this possibility does raise questions about transmission capacity and safety, as well as the implications of such a technology on the built environment.
According to the Hampton, Va.-based company, WiGL functions just like Wi-Fi. Like Wi-Fi routers, WiGL transmitters convey radio frequency (RF) signals through the air. In its case, however, WiGL delivers energy rather than information. The technology makes use of RF electromagnetic radiation (EMR), generating an electric field similar to that emitted by broadcast television or microwave ovens. Wi-Fi generates an electric field in the high-frequency range since RF radiation can carry information as well as energy. WiGL technology builds on established Wi-Fi standards. The Federal Communications Commission caps the Wi-Fi transmission rate at 1 watt at the 2.4-GHz frequency to maintain safe levels of RF exposure. Because WiGL adheres to this limit, the company claims its technology is safe for people.
WiGL is therefore limited to generating a low-level electric field. Because RF diminishes rapidly with distance, the WiGL system is designed as a transmitter array, forming a mesh network to deliver consistent RF power throughout a facility. The company is still experimenting with the spacing of this network, claiming that distances of 15 feet are currently viable. According to WiGL chief operating officer Robert Rickard, complying with the 1-watt limit means that the network can provide only 10% to 25% of the power and a recharging rate compared with a wired connection. That is, a smartphone in a WiGL field would require four to 10 times longer to recharge. However, because a device is continuously charging in a WiGL space, its low recharge rate may be perfectly acceptable so long as the device’s consumption rate is lower. Additionally, WiGL operates as a smart network, capable of identifying the needs of each WiGL-enabled device. “To put it into perspective, if you are about to go to bed and need to charge your smartphone, the system will recognize that it has an eight-hour window to send power and provide accordingly,” Rickard says.
WiGL’s physical distribution is the subject of ongoing study. Effective transmission depends on many factors, including room size and shape, the presence of RF-impeding physical barriers, and the use of omnidirectional or bidirectional transmission beams. WiGL’s current recommended mesh network spacing is eight- to 10-foot intervals. “Although it is true that power can be sent to around eight to 10 feet without wasting a considerable amount, the grid will have to consist of enough transmitters that will be able to provide power at any point in that space,” Rickard says. “The advantage of the system is that transmitters can be incorporated into plugs, ceiling fans, household devices, alarm systems, smoke detectors, and so on.” Mesh grids can also be distributed throughout urban environments, with WiGL transmitters embedded in utility poles, traffic lights, street furniture, and roadways.
Living in an always-on, device-charging electrical field is a fascinating concept that is quickly becoming a reality. WiGL is not alone: Energous, Ossia, Powercast, and WiTricity are offering similar capabilities, all motivated to supply the burgeoning constellation of battery-powered IoT devices with energy. Despite these services’ adherence to federal transmission limits, safety remains a concern—particularly as EMR mesh networks proliferate and the technology is adopted in regions beyond FCC or similar jurisdiction.
The arrival of wireless, touchless power suggests that we should be as careful to monitor the environmental consequences of the invisible systems we have created as much as we assess the ramifications of the visible ones. WiGL and its competitors are establishing a new kind of energy architecture that, although unseen, will have measurable spatial and technological repercussions. This architecture represents a simultaneously empowering and unsettling means of advancing human activity on the planet.
