DARPA zaps popcorn with laser power beamed 5.3 miles through air
- Reference: 1747675574
- News link: https://www.theregister.co.uk/2025/05/19/darpa_energy_beaming_record/
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DARPA says the Persistent Optical Wireless Energy Relay (POWER) team program [1]managed to transmit more than 800 watts of power from a laser emitter to a receiver located 5.3 miles (8.6 kilometers) away during a 30-second transmission. To celebrate the achievement, POWER used some of the transferred energy to make popcorn - an homage to Real Genius, the 1985 Val Kilmer film where slacker grad students thwart a plot to weaponize high-energy lasers.
For reference, 800 watts isn't a ton of electricity, but it's enough to run a small fridge, lights, or an RV setup. It's a practical start, assuming the tech scales as DARPA intends.
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And it's not just about popcorn and personal gadgets - DARPA has its eyes on the battlefield.
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The POWER program falls under DARPA's Tactical Technology Office, which seeks to develop systems that can be used in battlefield environments. Specifically, the program could help create military tech that's not constrained by battery limits or tethered power. DARPA said the program's results to date "mark an important step" toward that end.
It is beyond a doubt that we absolutely obliterated all previously reported optical power beaming demonstrations for power and distance
DARPA noted that previous attempts at wireless laser power transmission were considerably less effective than its POWER demonstration, with the previous record "for an appreciable amount of optical power" transmitting just 230 watts at a distance of 1.7 kilometers, or just a little over a mile.
"It is beyond a doubt that we absolutely obliterated all previously reported optical power beaming demonstrations for power and distance," POWER program manager Paul Jaffe said in a statement.
This particular test, the POWER Receiver Array Demo (PRAD), demonstated a new type of receiver technology for the laser beam. The receiver, designed by Teravec Technologies with support from Packet Digital and the Rochester Institute of Technology, features a compact aperture that allows the laser to enter with minimal light loss. Inside, the beam strikes a parabolic mirror that reflects it onto dozens of photovoltaic cells housed within the device, converting the laser light into usable electrical power.
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The PRAD receiver used in the recent POWER test - Click to enlarge
Not battlefield ready yet
DARPA said the receiver is designed "to be scalable to higher power levels and can be integrated into different platforms," such as unmanned aerial vehicles. But it will likely be a while before drones powered by high-energy lasers start buzzing overhead.
For starters, there's the issue of power transfer efficiency. The PRAD demonstration was simply meant to validate the receiver technology quickly, and did not focus on efficiency. DARPA reported that the system achieved just over 20 percent efficiency from laser output to electrical power at the receiver, but only at shorter distances. The agency didn't disclose the efficiency at the full 5.3-mile range, but it's safe to assume the real number is lower.
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That means the 800 watts received was just a slice of the total beam energy fired downrange. It's similar to the [7]current state of fusion power : scientists have been able to claim net-positive output from a fuel pellet - if they ignored the massive power bill for lighting the laser in the first place.
[8]DARPA wants to refuel drones in flight – wirelessly
[9]Caltech claims to have beamed energy to Earth from satellite
[10]US Army's laser obsession continues with yet another drone-zapper deal
[11]Look! Up in the sky! Proof of concept for satellites beaming energy to Earth!
Jaffe did tell The Register that improving its efficiency should be relatively easy, however.
"We made a few trade-offs in the components used to get a demonstration together quickly to prove out the underlying receiver design," Jaffe said in emailed comments. "Future receivers would have lighter parts as well as specialized photovoltaic cells optimized for the wavelengths of light we’d be using, which can be more than double or even triple the efficiency of a typical solar cell."
Still, it's an impressive feat, and the team is now preparing for Phase 2 of the POWER program, which kicks off with an Industry Day later this month.
Phase 2 aims to "demonstrate the benefits of integrated relays and vertical power transmission" and is currently seeking creative partnerships to help push the technology further. Registration for the Industry Day event closes on May 21. ®
Get our [12]Tech Resources
[1] https://www.darpa.mil/news/2025/darpa-program-distance-record-power-beaming
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aCup-x3ezlDjyunEIgjBOAAAAAk&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aCup-x3ezlDjyunEIgjBOAAAAAk&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aCup-x3ezlDjyunEIgjBOAAAAAk&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://regmedia.co.uk/2025/05/19/power-prad-receiver.jpg
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aCup-x3ezlDjyunEIgjBOAAAAAk&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://www.theregister.com/2022/12/14/nuclear_fusion_doe/
[8] https://www.theregister.com/2022/06/14/darpa_drone_wireless_charging/
[9] https://www.theregister.com/2023/06/07/satellite_energy_earth/
[10] https://www.theregister.com/2025/03/25/us_army_laser_weapon/
[11] https://www.theregister.com/2022/11/10/esa_space_based_solar_power/
[12] https://whitepapers.theregister.com/
General we have equipped all our drones with solar panels so they don't need batteries.
What happens at night ?
We thought of that, we have mounted a giant rotating light on a big tower at HQ.
Battlefields are constantly changing.
Does this thing have an automated method of maintaining the connection? How much power does that use? Around trees/hedgerows/buildings/rocks/hills/gullys? What does a light breeze or strong wind do to the alignment? How about atmospheric effects? (We've all seen heat shimmering blurring out traffic down a hot street or highway, over distances of yards, never mind a couple miles.) Rain, snow, sleet?
How do the optics handle the smoke, dust, dirt and general grime of a battlefield?
How do they let light in .... and keep bullets out? Bullet-proof glass is not 100% transparent.
What's it weigh, compared to (for example) a 1200W generator? Or a battery, which can be recharged with virtually any vehicle?
Come to think of it, what's the benefit of this thing over a series of gensets (fuel of choice) built into a dirt-bike, a SXS and a jeep? Could quite easily go 2kW, 4kW and 8kW on the three without too much difficulty, and also have the ability of being mobile, bringing in (some) supplies, evacuating the wounded, etc., as conditions warrant.
A century ago, Tesla (the man not the car) proposed transmitting all the world's power through air/space. He demoed small systems and Wardenclyffe was going to be world-wide. Naturally the Edison Cartel and Marconi's telegraph undercut his funding and reputation so they could keep billing for power and messages.
And there is exactly zero evidence that he could do what he claimed at scale, or without laughable inefficiency. Do you honestly believe that someone 100 years ago cracked this and today's leading scientists and engineers can't even make wireless transmission of power across a room work safely and efficiently?
Naturally the Edison Cartel and Marconi's telegraph undercut his funding and reputation so they could keep billing for power and messages
..............
Et alors la marmotte, elle met le chocolat dans le papier alu.
Speaking of papier alu - I still can't fathom the fact that tinfoil hats do feed the brains under them precious eyes-only information and deep secret knowledge from the source, BUT refuse to stream basic info on how Evil and business entropy really works...
Which is that - if Tesla had anything similar at an operational level - the Evil ones would have let him finish it then steal it from him and start charging for it, for an even greater profit.
So he had it ready, but they cut his wings. Somehow - they (the bad guys) had the power to sabotage Nikola Tesla's work, in an efficient and all-destroying way, BUT were scared crapless of the the mighty laws in the US that would have left them penniless should Tesla have finished his work :-P
This is deliciously cute cherry-picking.
The reality is that if free energy/wireless energy transmission/internal combustion engines running on water/fill the blanks here COULD and DID exist, the nasty ones would be the first to exploit them and make them PAID.
The free energy sources would be taxed, the area over which the wireless energy beam would flow would be taxed, the water that goes in that magic engine would get taxed, the blanks that were left to be filled with something else magic would be taxed too.
Most basic example - home heating diesel fuel in, say, France. Costs a fraction of what diesel at gas stations costs. There are heavy fines if you're caught using it in your car - with all the matching roadblocks, and chemical tracers in heating diesel that make it easy to detect by those smiling mobile customs. Rumor is there are also little chemical "aids" that would "help" your engine to an untimely death should you use heating diesel exclusively. But that's a rumor. The roadblocks at night - I've seen myself.
There is no vacuum in business and in taxes. There's no benevolent wise lawmen watching from the side, and no Johnny Mnemonic. If wireless electricity transmission was invented tonight at midnight, it would be taxed at one past midnight. And in the morning, we'll be celebrating the abolition of cables and poles, while still paying the same electricity bills or higher.
Ah, its amazing what they tell us these days.
They've been working on this since the late 1950s. The only real change over the last 50 years is that the equipment to generate the laser has shrunk in size, power consumption, and cycle time, and increased in durability/reliability.
I'm sure there are lawn ornaments that are 12" steel cubes with a hole burned through in back yards around Burbank.
This may work well as long as battlefields are always free from rain or smoke and have perfect unobstructed line of sight.
Also it might be a good idea to place this high up to avoid toasting too many grunts.
A laser and big parabolic dish about 20 feet off the ground would never be an inviting target so I can't see any problems here.
I just suppose it's a good thing no potential enemy has any form of IR vision because when you are painting your battlefield with bright lasers, you really would not want to give away your forward positions.