Imagine a world where drones never have to land to recharge, disaster teams can light up a collapsed bridge without laying a single cable, and remote sensors run indefinitely without bulky batteries. That vision is inching closer to reality thanks to DARPA’s latest innovation: the POWER project, short for Persistent Optical Wireless Energy Relay.
The U.S. Defense Advanced Research Projects Agency has pulled off something that sounds more like a cartoon contraption than military-grade science transmitting electricity across kilometers using focused beams of light. No wires, no fuel trucks, no batteries, just power turned into photons, sent through the air, and converted back again at the other end.
The system begins with a transmitter that converts electricity into a high-powered near-infrared laser. That beam is tracked and guided across open air until it reaches a receiver, where a small aperture admits the light onto a parabolic mirror. The mirror redirects the beam onto a rugged array of photovoltaic cells, which convert photons back into usable current.
Think of it as Wi-Fi for power: the same idea of going wireless, only this time with energy instead of data.
The breakthrough came at the U.S. Army’s White Sands Missile Range, where DARPA’s team managed to deliver more than 800 watts of power across 8.6 kilometers for 30 seconds. Over several days of trials, they successfully transferred more than a megajoule of energy in shorter bursts.
Efficiency wasn’t the headline goal, but the setup still achieved a little over 20 percent end-to-end conversion at shorter ranges. The demonstration smashed previous records in the field, which topped out around 230 watts at 1.7 kilometers. And in a lighthearted touch, the researchers even used some of the transmitted energy to make popcorn.
This doesn’t mean copper wires in your walls are about to vanish. Traditional grids remain cheaper, safer, and vastly more efficient for homes, cities, and factories. But POWER shines where cables are impractical: recharging drones mid-flight, powering emergency equipment in hard-to-reach areas, or keeping military bases running without vulnerable supply convoys.
Physics remains the biggest buzzkill. Fog, dust, and haze scatter beams and cut range. High-power lasers raise obvious eye-safety issues. And each conversion, bleeds efficiency. For now, the economics make sense only in high-value missions where flexibility outweighs raw efficiency.
DARPA’s roadmap includes airborne relays, pods on drones or high-altitude aircraft that can catch the beam, clean it up, and pass it along. With enough of these hops, the agency hopes to demonstrate delivery of 10 kilowatts across 200 kilometers. That would enable new forms of persistent flight, resilient communication nodes, and off-grid energy delivery in places where laying wires would take weeks or prove impossible.
In the long run, POWER isn’t about replacing cables but complementing them. Where wires are slow to lay, unsafe, or unfeasible, a temporary “line of light” could be the fastest way to bring power online. For everything else, copper still wins.