Scientists transmit electricity wirelessly over a distance of five miles using lasers

Lasers are not only for cutting metal or scanning groceries. They can also carry usable electricity across open air without a single wire.

A U.S. team sent electrical power as laser light across about 5.3 miles and turned it back into electricity at the far end.

They described 800 watts delivered during a 30 second burst, along with measured efficiency near 20 percent at shorter ranges.

Wireless electricity revolution

Electricity keeps everything running, from communications to clean water. Getting power to the edge of a battlefield or to a disaster zone is slow, risky, and expensive when it depends on fuel trucks.

Beaming power on demand could change that by removing long supply lines. It could also support off grid sensors and remote research stations that now rely on heavy batteries or generators.

The method is called optical power beaming, and it converts electricity into a tightly controlled laser that travels through air to a specialized receiver.

At the receiver, a parabolic mirror – a curved reflective surface shaped like a dish that concentrates incoming light to a single point – focuses the light onto photovoltaic cells, which then convert the light back into electrical power.

In this system, a compact aperture helps trap incoming light so very little escapes once it enters the receiver. That detail matters because any light that leaks is wasted energy and potential hazard.

What made this test different

The 5.3 mile link was not a straight shot into clear sky. It crossed the thickest, dustiest part of the atmosphere near the ground, which is the hardest path for a clean optical beam.

Over the course of the tests, the team transferred more than a megajoule of energy, a benchmark that adds up when you consider how short each shot was.

The work took place at the U.S. Army’s White Sands Missile Range, a site built for high energy laser experiments.

A key advance is the Power Receiver Array Demo (PRAD) receiver. The device routes the incoming beam to dozens of solar cells arranged around the inner surface so each cell shares the load.

The receiver was designed and built in about three months and is described as modular and scalable to much higher power levels. That kind of scalability is essential if future systems need to feed vehicles or mobile bases.

Lasers and wireless electricity

A program manager at DARPA said the team’s achievement far surpassed all earlier demonstrations of optical power beaming in both power and distance, adding that the result challenged long-held assumptions about how far laser transmission can reach.

Before this, public demonstrations reached shorter distances or lower power. The new mark pushes both at once, which is why it stands out.

Uncrewed aircraft are an obvious target for early use. A receiver onboard a drone could take a charge mid flight and stay aloft much longer without landing for batteries.

The program’s broader plan is to place relays in the sky to create long chains of energy links. That would allow vertical shots where the atmosphere is thinner and cleaner, which makes each hop more efficient.

Safety, efficiency, and limits

No technology is magic, and beaming power has tradeoffs. Eye safety, beam control, and air quality are front and center, and systems include shutters, sensors, and geofencing to keep beams away from people and aircraft.

Turbulence, aerosols, and heat can scatter light and lower efficiency, especially near the ground. Choosing the right wavelength, improving adaptive optics, and keeping paths short can help.

Engineers have studied wireless optical power for decades. Early work focused on lab benches and short indoor links.

A paper describes how the current program aims to build a flexible energy web using airborne relays. That concept borrows ideas from communications networks where multiple hops beat one long fragile link.

How this fits in the bigger picture

This kind of system will not replace the grid. It complements wires by serving places that wires cannot reach quickly or safely.

In emergencies, a temporary optical link could power water pumps, clinics, or communications hubs while crews restore lines.

In defense settings, it could cut the number of fuel convoys on the road, which reduces risk to people.

Questions about wireless electricity

What happens in fog or dust. The short answer is that thick haze can scatter the beam and reduce output, which is why planners prefer higher altitude legs or shorter paths near the ground.

Could it work from space? Yes, though the engineering is hard, and any space to ground link must manage safety, aiming, and atmospheric heating with great care.

What to watch in the next phase

The next step is showing relays that catch a beam and pass it on without losing too much. That proof will show whether long chains are practical.

Another milestone is powering moving targets. Keeping a tight spot of light on a small receiver on a UAV, an unmanned aerial vehicle commonly known as a drone that flies without an onboard pilot, is not easy, so tracking and stabilization must be excellent.

Wireless electricity and the future

The project shows how physics, materials, and control systems meet real needs. It links concepts students learn in optics and electricity to a working system with measurable results.

It also shows why design choices matter. A compact aperture, a parabolic mirror, and well matched solar cells add up to a receiver that wastes less and delivers more.

Sending hundreds of watts across miles of air is now a repeatable demonstration. The pace of progress has surprised people who thought the atmosphere would always be the showstopper.

More work remains, but the door is open. The core pieces are on the table, and the rest is engineering and careful testing.

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