Drones that never need to land to recharge their batteries? Or military equipment powered without a single electrical cable? This is exactly what DARPA (Defense Advanced Research Projects Agency) has just demonstrated during spectacular tests in New Mexico.
Drones with unlimited range
The American military research agency has achieved the feat of transmitting more than 800 watts of power over a distance of 8.6 kilometers, using only a laser beam. To give you an idea, this is enough to power a small refrigerator, lighting, or all the electronic equipment in a camper van. For 30 seconds, the energy traveled through the air without any physical support.
The team even had fun making popcorn with the electricity received, a nod to the film Real Genius, where students hijack a military laser. "There's no doubt that we completely blew away all previous demonstrations," enthuses Paul Jaffe, head of the POWER program. The previous record? Only 230 watts over 1.7 kilometers.
This technology could be a game-changer for military equipment. No more hassle with trailing power cables, no more running out of power at the wrong time, and above all, no more autonomy limits for drones. They could theoretically fly indefinitely, continuously powered by ground-based laser stations.
The system tested, called PRAD, works with a compact receiver developed by Teravec Technologies. The principle is simple: the laser beam hits a specially designed aperture, hits a parabolic mirror inside, and then travels to dozens of photovoltaic cells that convert the light into electricity. All without losing too much energy along the way.
"It's much easier to send a beam up or down than horizontally because there's less atmosphere to travel through. We wanted to test it in the worst-case scenario," explains Paul Jaffe. And it clearly works even in these difficult conditions. This technology could revolutionize military logistics. No more need to transport fuel to remote areas at the risk of being detected, no more noisy generators that betray positions. A simple laser beam is enough to power equipment remotely.
For now, efficiency is not optimal: only 20% of the laser energy is converted into electricity over short distances, and even less over 8.6 kilometers. But Paul Jaffe remains optimistic: "We made compromises on components to go faster. Future receivers will use specialized photovoltaic cells that can double or triple the efficiency."
DARPA is now preparing Phase 2 of the program, which aims to test vertical transmission and relay systems. The idea is to create a true wireless power distribution network.
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