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A new technology shoots laser beams at drones to charge them in midair, thus unlocking the possibility of “infinite flight.”
Representatives from PowerLight Technologies say the system works by pairing a ground-based transmitter with a receiver on the drone, also known as an unmanned aerial system (UAS). The transmitter combines advanced software designed to provide precise control of the laser beam with hardware that can sustain power transmission on a scale of kilowatts — or thousands of watts — according to the company. For comparison, typical lab lasers operate on a scale of milliwatts, or thousandths of watts.
For context, the operational altitude of the Raven RQ-11B — a hand-launched intelligence, surveillance and reconnaissance drone developed for the U.S. military — is between 150 and 1,000 feet (46 and 305 meters) above ground level, and 10,500 feet (3,200 meters) above sea level. Larger drones can reach altitudes as high as 60,000 feet (18,288 m).
Integrated control software can also link up with software on the UAS to provide telemetry monitoring and control. This interoperability means that data and commands can be exchanged between PowerLight’s tracking and beam control system, and the drone’s onboard avionics and telemetry system. This could be used to send battery charge information to operators on the ground, who could dynamically alter power delivery, and ensure that it’s being delivered efficiently while the laser is on always on target.
“We are building an intelligent mesh energy network capability,” said Tom Nugent, chief technology officer and co-founder of PowerLight, in a statement. “Our transmitter communicates with the UAS, tracks its velocity and vector, and delivers energy exactly where it’s needed. We have now successfully tested the power transmission and tracking algorithms.”
Endless flight
A receiver is built into the drone itself. This receiver, which weighs only 6 pounds (2.7 kilograms), captures the laser energy from the ground-based transmitter and uses a laser power converter to turn it into battery power.
Photovoltaic laser power converters operate similarly to solar cells, capturing light and transforming it into an electrical current. However, they are optimized for monochromatic, high-intensity laser light rather than broad-spectrum sunlight.
The receiver also includes an embedded control module. This module continuously gathers real-time telemetry about the drone’s position and operation and relays that information to operators on the ground. It’s also capable of establishing a two-way light-based communication link that allows it to both send and receive information using optical signals.
The system was developed in conjunction with the U.S. Department of Defense (DoD). It will be integrated into the K1000ULE, a long-range, high-endurance drone developed by Kraus Hamdani Aerospace. The K1000ULE is fully electric and engineered for persistent, long‑range missions in support of the U.S. Navy and Army.
Previous testing has shown the potential for wireless power transfer through lasers. For example, the Defense Advanced Research Projects Agency demonstrated a power transfer of more than 800 watts delivered from a laser 5.3 miles (8.6 kilometers) away).
However, the PowerLight system is a step toward real-world deployment in mobile platforms. Recent testing has proved the viability of the transmitter and receiver, but PowerLight has yet to conduct flight tests, which are scheduled for early this year.
