It almost sounds like science fiction, but DARPA, the agency responsible for the development of emerging technologies in the US military, used a laser to send electricity across miles of open air. Researchers beamed over 800 watts of power across 8.6 kilometers (5.3 miles) of atmosphere. Then, just to prove the point, they made popcorn with the transmitted energy.
“It is beyond a doubt that we absolutely obliterated all previously reported optical power beaming demonstrations for power and distance,” said Program Manager Paul Jaffe after the results were confirmed.
From laser to electricity
The demonstration is part of DARPA’s Persistent Optical Wireless Energy Relay (POWER) program. The program aims to make energy delivery as mobile and instant as wireless communication. It could one day send electricity through the air to military bases, disaster zones, or remote installations. The approach is bound to be more inefficient than transmitting electricity through wires, but it offers an alternative where wires don’t exist, especially mobile or high risk situations where logistics matter more than efficiency.
In principle, this works by converting electricity to laser light. This light is beamed through the atmosphere and enters a parabolic mirror which then reflects onto dozens of photovoltaic cells. These photovoltaic cells reconvert the laser energy back to usable power.
The main problem here is the atmosphere. Even under ideal conditions, each stage introduces inefficiencies, and atmospheric scattering, absorption, and alignment challenges further reduce the overall energy delivered compared to what’s sent. DARPA’s recent demonstration achieved over 20% efficiency at short distances which is absolutely remarkable, but it’s still way less than the 95% efficiency that most electrical transfer systems have.
The key innovation lies in capturing the beam with minimal light leakage and converting it quickly and reliably — even across long distances and through thick atmosphere. The scale is also flexible. The same receiver technology could someday be mounted on drones, vehicles, or remote stations, any place where getting power is difficult or dangerous.
A new record
Previously, the greatest reported distance record for a significant amount of power was 230 watts of average power at 1.7 km for 25 seconds. There was also another experiment for an undisclosed amount of power at 3.7 km. The current achievement is greater not only in distance, but also in power.
During the record-breaking test, the DARPA team successfully beamed over 800 watts of power across 8.6 kilometers (5.3 miles). That’s roughly the same amount of power needed to run a microwave oven, a toaster, or a small window air conditioner.
Over the full series of tests, they transferred more than one megajoule of energy in total. To put that in everyday terms, that’s enough energy to boil about 10 liters (2.5 gallons) of water or fully charge a laptop 25 times. In fact, the team used the energy to make popcorn — a nod to the 1985 movie Real Genius, where a laser was used to pop an entire room full of popcorn.
For the test, the team had both the transmitter and receiver on the ground , which means the beam had to travel through the thickest part of the atmosphere—a much harder test than beaming straight up into the sky.
“It’s a lot easier to send a power beam directly up or down relative to the ground because there is so much less atmosphere to fight through,” Jaffe explains. “For PRAD, we wanted to test under the maximum impact of atmospheric effects.”
So what’s next?
DARPA is already gearing up for Phase 2, which will explore even more ambitious goals: adding relay stations, beaming power vertically, and moving from prototypes to real-world applications.
This record-setting laser experiment is the clearest signal yet that power beaming is leaving the realm of fantasy and entering the toolbox of 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 work has not been published in a peer-reviewed journal.
