Imagine a world where power lines are replaced by laser beams, beaming electricity across miles of air to wherever it’s needed. This futuristic vision is no longer confined to science fiction: DARPA’s Persistent Optical Wireless Energy Relay (POWER) program has just shattered previous benchmarks, demonstrating that wirelessly transmitting hundreds of watts over several miles is feasible today.

In both military operations and humanitarian missions, reliable power at remote locations can mean the difference between success and failure—or even life and death. Forward operating bases, disaster-relief encampments, field hospitals, and sensor outposts all depend on electricity for communications, medical devices, computing, and more. Traditionally, this means hauling fuel convoys, portable generators, or bulky power infrastructure into austere environments—tasks fraught with logistical complexity, expense, and vulnerability to attack or disruption.

The “last mile” of energy delivery is especially brutal: where roads are nonexistent or too risky to traverse, soldiers and aid workers resort to physically hauling jerry cans of fuel over rugged terrain. Even when fuel or generators arrive, maintaining a steady supply chain in hostile or disaster-stricken regions remains a major challenge. Given that energy is often described as the “fundamental currency of the battlespace,” reducing or eliminating these supply burdens could transform expeditionary operations and humanitarian relief alike.

DARPA’s POWER program aims to build a resilient, multipath “energy web” by using lasers to send power near-instantaneously from where it can be generated to remote receivers, potentially via airborne relay nodes. The concept: a ground-based high-energy laser emits a beam that travels through the atmosphere to a receiver array, which converts the light back into electricity via photovoltaic cells. By incorporating relay platforms—drones or aircraft equipped with optics to redirect or amplify the beam—the system could route power around obstacles and extend its reach over even greater distances.

Phase One, known as the Power Receiver Array Demo (PRAD), focuses on validating the core receiver technology and proving that significant amounts of power can be sent over miles of ground level air. Subsequent phases will tackle airborne relays, wavefront correction, scalability to higher power levels, and eventually end-to-end demonstrations involving multiple relay nodes mounted on conventional aircraft to deliver tens of kilowatts across hundreds of kilometers.

In a series of tests at New Mexico’s High Energy Laser Systems Test Facility (HELSTF) at White Sands Missile Range, DARPA’s team recorded a new milestone: over 800 watts of power delivered during a 30-second laser transmission across 8.6 kilometers (5.3 miles) of ground-level air. Previously, the best reported demonstration had been 230 watts over 1.7 kilometers for 25 seconds, plus an undisclosed amount at 3.7 kilometers. The latest achievement thus obliterates earlier benchmarks for both power and distance.

According to program manager Paul Jaffe, “It is beyond a doubt that we absolutely obliterated all previously reported optical power beaming demonstrations for power and distance.” Beyond bragging rights, transferring over a megajoule of energy during this test campaign signals tangible progress toward delivering practical power amounts: 800 watts could run lights, charge batteries, power small refrigeration units, or support communications and sensor nodes at remote sites.

At the heart of the demonstration is the POWER Receiver Array Demo (PRAD), a spherical or ball-like structure with a compact entrance aperture engineered to minimize losses as the laser enters. Once inside, the beam strikes a parabolic mirror that uniformly distributes the light onto an array of photovoltaic cells lining the interior. These cells convert the concentrated laser energy back into electrical power. Design priorities for Phase One emphasized extending distance and power capacity rapidly, even at the expense of efficiency.

Despite focusing on distance and power, the prototype receiver achieved about 20% conversion efficiency at shorter ranges—a respectable figure given the short development timeline (the custom receiver was reportedly built in just a few months). DARPA plans to improve efficiency in later phases by refining optical designs, enhancing photovoltaic materials, and optimizing alignment and wavefront correction.

Transmitting laser beams through the atmosphere presents several challenges: absorption and scattering by air molecules, turbulence-induced beam distortions, weather sensitivity (fog, rain, dust), and safety concerns for overflight of aircraft or wildlife. Conducting the tests at ground level—where the atmosphere is thickest—was intentional: demonstrating robust performance under the worst-case atmospheric conditions makes future high-altitude or space-to-ground links easier by comparison.

Maintaining precise beam alignment over miles requires advanced tracking and adaptive optics to correct for atmospheric turbulence. Relay nodes mounted on drones or aircraft will add complexity: they must detect incoming beams, adjust pointing in real time, and redirect or re-amplify the beam toward the next node or final receiver. Ensuring eye and airspace safety means developing strict operating procedures, protective measures, and possibly restricted zones or coordination with aviation authorities.

Phase Two of POWER will mature and demonstrate ground-air-ground relay links, testing simulated high-altitude relay payloads at HELSTF. The ultimate vision: a network of airborne optical relay nodes—potentially three or more—hosted on manned or unmanned aircraft at altitudes around 60,000 feet, capable of passing laser power from a ground source to remote receivers up to 125 miles away. This multi-hop approach could bypass terrain obstacles, reduce atmospheric losses by operating above the densest layers, and provide on-demand power to forward locations without fuel convoys.

DARPA has already solicited industry partners to design relay payloads, with contracts awarded to firms like RTX (Raytheon), Draper, and BEAM Co. The plan is to integrate these relays onto existing platforms, validate wavefront correction, beam steering, and energy harvesting in flight-like scenarios, then scale up lasers to higher power levels to deliver kilowatts rather than hundreds of watts.

By Phase Three, the goal is to field systems capable of delivering around 10kW of optical energy over distances on the order of 200km, enabling truly expeditionary power distribution networks. At that stage, applications could include charging long-endurance UAVs in flight, powering field hospitals, sensor arrays, or communications hubs, and even supporting drones or electric vehicles in remote areas without fuel logistics.

While military use drives initial funding and development, optical power beaming holds promise for civilian and space applications. Disaster-relief scenarios—where infrastructure is destroyed—could benefit from rapid deployment of ground-based lasers and receivers atop drones or tall structures to restore electricity to critical facilities. Remote research stations, off-grid communities, or maritime installations might draw power without undersea cables or fuel shipments.

In space, laser power beaming is studied for transmitting solar energy collected by orbiting satellites down to Earth, or between spacecraft. Paul Jaffe’s ongoing research, including the Space Wireless Energy Laser Link (SWELL) experiment, explores these concepts: beaming power in space to satellites, spacecraft, or lunar/martian bases. Advances in atmospheric power beaming feed directly into space applications by improving receiver designs, beam steering, and adaptive optics.

Deploying high-energy lasers raises safety and regulatory issues: ensuring beams avoid aircraft, satellites, wildlife, and populated areas requires robust tracking, automatic shutoff systems, and coordination with aviation and regulatory bodies. International treaties and export-control regimes (e.g., ITAR) may govern dual-use laser and optical technologies. Ethical considerations include preventing misuse: adversaries could attempt to weaponize beam technology or target relay nodes. Transparent testing protocols, oversight, and safeguards will be essential as the technology matures.

DARPA’s recent record-breaking demonstration is a pivotal proof point: it shows that laser-based power beaming can exceed previous limits by orders of magnitude. However, scaling from 800 watts at 5.3 miles to 10 kilowatts at 125 miles entails overcoming technical, logistical, and regulatory hurdles. Adaptive optics must become more agile, receivers more efficient, and relay platforms more robust. Meanwhile, operational concepts for employing such energy webs in contested environments will need development.

Still, the momentum is building. Industry partnerships and academic research are exploring novel photovoltaic materials optimized for laser wavelengths, lightweight steerable optics, and autonomous beam-tracking algorithms. As these components progress, the vision of a near-instantaneous energy network—where power follows the user rather than users chasing power—edges closer to reality. Whether for soldiers at the edge, disaster relief teams, remote communities, or even future space settlements, laser-based power beaming could redefine how we think about delivering electricity. And while challenges remain, DARPA’s recent milestone suggests that the age of wireless power delivery through beams of light is dawning sooner than many might have thought.