Laser power transmission pushes drones closer to continuous flight
U.S. defense-backed engineers and private companies are advancing wireless power systems that could recharge drones in midair and sharply extend endurance.
The effort targets one of the biggest limits on electric unmanned aircraft: battery life. If that constraint can be eased, drones could stay on station longer, avoid risky or impossible landings, and continue missions without interruption. Two main technical paths are emerging. One uses far-field electromagnetic power transfer. DARPA began backing that line of work in 2021, funding research aimed at steering electromagnetic waves with enough precision to charge drones in line-of-sight flight. That work later fed into KinetixBeam, a company developing long-range wireless power systems based on phased arrays, reconfigurable metasurface lenses, and conformal rectennas.
DARPA has also been testing optical power transfer. In New Mexico, its Persistent Optical Wireless Energy Relay, or POWER, system delivered 800 watts over 5.3 miles, or 8.6 km, using a specialized transmitter and a receiver developed by Teravec Technologies. The test set a new benchmark for optical wireless energy transfer, though it used ground equipment rather than an aircraft. Closer to field use is PowerLight Technologies, a Washington state engineering company that has spent roughly two decades working on laser-based power beaming. The company said in December it had successfully developed and tested a system capable of delivering kilowatt-class power to a drone flying at 5,000 ft, or about 1,524 m, and said its non-visible laser beam can transmit energy over distances measured in kilometers.
PowerLight has built a portable transmitter that can track and lock onto airborne drones, while also incorporating beam safety features and real-time monitoring and control. The system takes electricity from a battery, converts it into high-intensity light, and sends that energy through the air as a non-visible laser beam to a receiver mounted on the aircraft. The onboard receiver then converts the light back into electrical power using a photovoltaic cell array. In recent tests, PowerLight mounted a 6-lb, or 2.7-kg, receiver on a K1000ULE long-range electric drone made by Kraus Hamdani Aerospace, a platform used by the U.S. Navy and Army. The company said its transmitter and receiver subsystems are now entering the final stages of validation, with fully integrated flight trials on the K1000ULE planned for this year.
If the technology proves reliable in operational settings, it could materially expand what electric drones can do. Longer airborne endurance would benefit defense support, reconnaissance, search and rescue, and inspection roles such as oil and gas pipeline monitoring. It could also support longer-duration drone operations in cities for traffic management, air pollution monitoring, and other public-service tasks. The broader implication is clear: for some drone missions, the key limit may shift from battery capacity to system deployment and airspace safety.