New technology would enable U.S. to recharge drones in flight


Anyone considering buying an electric vehicle has heard of “range anxiety” — the fear of running out of power on a trip and not being able to find a charging station.

The U.S. Department of Defense (DOD) is taking a step to avoid such worries.

The startup Electric Sky Inc. announced in a news release December 7, 2021, that it is building the world’s first “Whisper Beam” transmitter for the wireless charging of in-flight unmanned aerial vehicles (UAVs), commonly known as drones, with an initial funding of U.S. $225,000 from the Defense Advanced Research Projects Agency (DARPA).

In the nascent technology, “radio waves self-focus at the receiver, enabling UAVs to draw kilowatts of power in all weather. The waves are weak everywhere else, even directly between transmitter and UAV,” according to the Electric Sky news release.

(Pictured: A U.S. Marine launches a Raven drone during 2020 training in Norway.)

“It’s a myth that long-distance power transmission is impossible, it’s just never been economical,” Whisper Beam inventor Jeff Greason said in the news release. “This new method reduces the cost of the ground transmitter and the size of the vehicle’s onboard receiver.”

CEO Robert Millman said that Electric Sky’s goal is to add the range needed for UAVs to outperform those powered by fossil fuels.

“Electric flight is more economical and environmentally-friendly,” he said in the news release.

Millman cautioned that DARPA’s interest in Whisper Beam is in the early stages. Still, if Whisper Beam works, the technology could be a boon for U.S. Soldiers, according to a December 16 story by the Task & Purpose military news website. For example, Whisper Beam could potentially keep the small, affordable drones used by the military for intelligence and surveillance flying for longer without interruption.

“Energy is a fundamental currency in the modern battlespace,” Air Force Lt. Col. Paul Calhoun, program manager for the project at DARPA’s Tactical Technology Office, told Task & Purpose. “Developing a more flexible, adaptive, resilient energy ‘web’ by leveraging wireless power transfer provides a potential breakthrough capability for national defense.”

Electric Sky isn’t the only venture focusing on wireless power for drones. The technology news website GeekWire reported December 7 that Seattle-based PowerLight Technologies is working on a laser-based system that could power up unpiloted aerial vehicles as well as 5G base stations.