DARPA Manages To Transmit Electricity Remotely Without Wires

That vision is inching closer to reality thanks to DARPA’s latest innovation: the POWER project. Since electric power was developed for prod...

That vision is inching closer to reality thanks to DARPA’s latest innovation: the POWER project.

Since electric power was developed for productive use in the late 19th century, power has been delivered to consumers via overhead and underground conductors. The delivery system gradually evolved into today’s power grid, a maze of transmission and distribution lines spreading across the country. While Nikola Tesla is credited with his development of alternating current lines, he also had the vision of using electromagnetic waves to transmit electric power. To this end, he conducted extensive experiments at his Long Island, New York, laboratory.

The telegraph started the telecommunications industry in the 1840s. For decades, the telegraph and later telephone systems required physical conductors to send and receive messages. Around 1900, wireless telegraphy was developed by Guglielmo Marconi. This remarkable achievement opened the door for wireless technology in the telecommunications industry. In the 1930s, microwave technology was introduced for use in the military. More improvements in wireless transmission prompted the removal of telephone pole lines across the country.

Fiber optics were born in the early 1960s. In 1968, NASA used fiber optics in conjunction with television cameras sent to the moon. Cellular technology began in the 1970s and would be a game changer. Interestingly, while wireless technology has eliminated the need for lines with conductors, fiber optics require pole lines or underground facilities to place the cable. Most fiber-optic cable installations utilize existing wood pole lines that support electric power lines.

The Wireless Transmission of Electric Power

Wireless power transfer (WPT) is the transmission of electrical power without wires and is based on technologies using time-varying electric, magnetic, or electromagnetic fields. Most of the early efforts for wireless power transfer used microwave frequencies as used with Wi-Fi and Bluetooth. These efforts have been successful, and hold promises for future applications such as wireless device charging. However, larger volume power transfers over longer distances is beyond the capability of microwave frequency technology.

Laser-based power beaming has emerged as a promising technology for longer-distance WPT. This system uses a power supply that generates a laser beam of light energy through the air to a photovoltaic receiver, where the light energy is converted back to electricity.

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word “laser” is an acronym for “light amplification by stimulated emission of radiation.”

New Zealand’s second biggest utility, Powerco, is in the process of conducting a test of its system at a grid-connected commercial power station. The company hopes to bring energy to communities far from the grid or transmit power from remote renewable sources, like offshore wind farms. Several other research projects are experimenting with laser-based power beaming, which is the most promising technology for longer-distance electric power transmission.

The U.S. Defense Advanced Research Projects Agency (DARPA) has made headlines with its POWER program, successfully transmitting electricity remotely without wires. In a series of tests at the U.S. Army’s White Sands Missile Range in New Mexico, the POWER team delivered more than 800 watts across 8.6 kilometers for 30 seconds. They repeated shorter runs over several days, transferring more than a megajoule of energy in total.

A sketchy drawing made by Nikola Tesla on January 7th, 1905.

The centerpiece of the demonstration was a new receiver system that allows a near-infrared beam to enter through a small aperture, strike a parabolic mirror, and reflect onto an array of commercial photovoltaic cells. At shorter ranges, the setup achieved a conversion efficiency of slightly over 20% from laser optical output back into usable electricity. While not the peak efficiency, the goal was speed, ruggedness, and demonstrating the feasibility of optical power beaming in field conditions. The achievement also set new records, surpassing prior optical power-beaming milestones, such as approximately 230 watts at 1.7 kilometers. Amusingly, the team even used a portion of the transmitted power to pop popcorn.

Will Copper Cables Become Obsolete?

Not exactly. This kind of wireless electricity won’t replace copper wires in homes, factories, or city grids anytime soon. But it does solve challenges that traditional cabling cannot. For example, drones could be powered continuously without landing for recharging, emergency teams could restore electricity across collapsed bridges, and remote sensors could operate without heavy batteries. In such scenarios, commanders and responders can move electricity on demand, bypassing fuel trucks and vulnerable distribution lines. For dense urban environments and the common power grid, traditional wires remain cheaper, more reliable, and highly effective. The novelty system demonstrated by POWER complements, rather than replaces, existing infrastructure.

Physics imposes several practical limits. Atmospheric conditions—haze, fog, dust—scatter light, reducing range much like solar panels underperforming on cloudy days. High-power beams require strict safety management to prevent eye hazards, and the beam must maintain precise tracking so it stays on target. Additionally, energy conversions—from electricity to laser and back—incur efficiency losses, making end-to-end numbers modest for now. While the White Sands tests proved the system rugged and repeatable, the economics only make sense in high-value or hard-to-reach missions.g

DARPA’s roadmap includes airborne relays: pods on aircraft or high-altitude platforms that receive, clean up, and pass along the beam. With multiple hops, operators could draw power from a generator and “lay” temporary lines of light across mountains or oceans. Later phases of the program aim to demonstrate a relay chain delivering roughly 10 kilowatts over 200 kilometers. This capability could support persistent flight for uncrewed aircraft, resilient communications nodes, and austere bases that need electricity when hauling fuel or installing cable would take days.

Applications 

While the military applications are immediate, there is potential for civilian uses in remote or disaster-struck areas. Imagine emergency response teams bringing temporary power to regions after hurricanes or earthquakes without waiting for trucks to deliver generators or technicians to string cables. Remote research stations, islands, or offshore platforms could also benefit, receiving power on-demand without laying expensive submarine cables.

In the space sector, wireless power beaming could be revolutionary. High-altitude drones or stratospheric platforms could receive continuous energy to maintain station-keeping for months, and future lunar or Martian bases might tap beamed energy from orbiting solar satellite