Technology

DARPA looks to laser to beam power across the world

Lasers and aerial relays could beam power over vast distances
DARPA
Lasers and aerial relays could beam power over vast distances
DARPA

In a move that sounds like the wildest of science fiction, DARPA has announced its new Persistent Optical Wireless Energy Relay (POWER) program that plans to use lasers relayed by airborne platforms to power machines thousands of miles away.

There are a lot of potentially brilliant technologies out there that could change the world but stumble on one fundamental limitation – how to power them. This is especially true for aircraft. Electric planes sound like a great idea, but the batteries needed to power them are so bulky and so heavy that they eat up valuable payload and range.

For over a century, the idea of the wireless broadcast transmission of power seemed like the obvious solution, but things like the basic laws of physics kept getting in the way. Now, DARPA is looking at using lasers to beam power from a ground source to distant receivers, providing, for example, electric aircraft with virtually infinite range.

In theory, this seems simple enough, but there are all manner of technical problems to be overcome. Lasers work along line of sight, so airborne relays are needed in the upper atmosphere to minimise the distortion and attenuation caused by air and water vapour. Also, like laser weapons, the transmitter and relays need to be able to lock on target and correct the beam to stay focused.

However, the biggest problem is the massive losses caused by changing laser light to electricity and back across multiple hops.

According to DARPA, POWER is in the first phase, which involves developing conceptual designs for the relays. The second phase will concentrate on integrating the technology into an existing airframe, and the third will be a test to deliver 10 kilowatts of laser power across 200 km (125 miles).

"This project has the potential to advance power beaming by orders of magnitude, which could radically reshape society’s relationship with energy," said Dr. Paul Jaffe, leader of the POWER program at DARPA. A wireless energy web could unlock power from new and diverse sources, including from space, and rapidly and reliably connect them to energy-starved consumers.

"Energy underpins every human activity, including defense. We need ways to deliver energy that overcome the vulnerabilities and other shortcomings of our current paradigm. The next leap forward in optical power beaming could hinge on relay technologies."

Source: DARPA

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7 comments
Ric
This will require a lot of redundancy or be an easy target for terrorists and enemy forces.
vince
Beaming laser power could also work wonders with space based PVC solar panels which in theory could beam power 24/7 even as losses as significant who cares when power level is order of magnitude higher in space so you lose some you gain some but moatly gain 24/7 power.
Cymon Curcumin
The Pentagon is a good place to develop this tech since military missions can tolerate much higher levels of inefficiencies if it gets something crucial done that can’t get done any other way. Powering a base or craft in a way that doesn’t risk the energy supply being cut off if you lose a road is handy, even if it wouldn’t be budget worthy for a private sector/non-life and death project. But I’m still skeptical of using it as a replacement for wires and fuel in non-military applications.
Jinpa
Before Nikola Tesla, there was E. E. Smith and his Lensman series of SciFi books, exploring this concept.
Sparty
I think the first receiver should be on Mar-a-Logo
TpPa
The best show of proof of concept to the world would be power the big ball in New York on new years eve
Rayswin
I contend that the biggest problem is not the massive losses of conversion but the effects by and on other airspace users who range from birds to light aircraft and increasingly to drones and flying cars. In general non aviation people do not realise there are so many more air uses than airliners.