In a breakthrough that sounds like something from a science fiction movie, the US military's DARPA (Defense Advanced Research Projects Agency) has successfully beamed electricity across miles using a laser. This remarkable feat, announced recently, involved transmitting over 800 watts of power across a distance of 8.6 kilometers (5.3 miles) through the atmosphere.
The project, part of DARPA's Persistent Optical Wireless Energy Relay (POWER) program, aims to make energy delivery as mobile and instant as wireless communication. The team even used the transmitted energy to make popcorn, a playful nod to the potential of this technology. Program Manager Paul Jaffe confirmed the impressive results, stating that the demonstration "absolutely obliterated all previously reported optical power beaming demonstrations for power and distance."
The technology works by converting electricity into laser light, which is then beamed through the atmosphere. A parabolic mirror captures the light and directs it onto photovoltaic cells, which convert the laser energy back into usable power. While atmospheric conditions pose a challenge, the recent demonstration achieved over 20% efficiency at short distances, a significant achievement.
The implications of this discovery are vast. It could revolutionize energy delivery to military bases, disaster zones, and remote installations where traditional power lines are impractical or dangerous. The ability to beam power to drones, vehicles, and remote stations opens up new possibilities for various applications.
DARPA's success surpasses previous records, which involved significantly less power and shorter distances. The team transferred over one megajoule of energy during the tests, enough to boil about 10 liters of water or fully charge a laptop 25 times. DARPA is already planning Phase 2, which will explore even more ambitious goals, including relay stations and vertical power beaming.
This groundbreaking achievement signals a shift from the realm of fantasy to real-world energy solutions. "This demonstration broke through misconceptions about the limits of power beaming technology, and it is already spurring industry to reimagine what's possible," said Jaffe. The future of energy delivery may very well be written in light.