S

ince the dawn of space exploration, the idea of harvesting solar energy in space and transmitting it to Earth has been regarded as a fascinating but purely science-fictional hypothesis. Today, however, the prospect of capturing solar power outside the atmosphere is becoming increasingly realistic, thanks to technological breakthroughs and plummeting launch costs.

Space-Based Solar Power (SBSP)—a technology that captures sunlight via massive satellite-mounted photovoltaic panels and transmits it to Earth using microwaves or lasers—is once again a prominent topic in both scientific and geopolitical circles.

 

 

Back when it seemed like science fiction

Science fiction writer Isaac Asimov first imagined this potential in 1941 in his short story “Reason,” describing a robot-operated space station that collected solar energy and beamed it to Earth via microwaves.

Remarkably, only fifty years before Asimov, Nikola Tesla—the enigmatic Croatian immigrant who transformed American industry—first demonstrated the technique for wireless energy transfer. Tesla was responsible for pioneering discoveries in alternating current, fluorescent lighting, hydroelectric power, and even radio. While the debate over whether Tesla or Guglielmo Marconi truly “invented” the radio continues, Tesla successfully lit vacuum tubes wirelessly by exploiting electrical resonance. By turning lights on and off remotely through wave frequency adjustment, he proved that electromagnetic flows could transfer energy without wires.

One day, these same types of radio signals could deliver energy from outer space—a dimension now largely dominated by the rockets and satellites of Elon Musk. The SpaceX founder is an outspoken admirer of Tesla, viewing him as an underrated genius and a primary source of inspiration for technological innovation, even naming his electric car company in his honor. As a central figure in Big Tech spanning space, mobility, robotics, and AI, Musk’s interest in Tesla’s legacy underscores how energy lies at the heart of modern entrepreneurial capitalism and will be central to the exploitation of space resources.

For decades, however, the scientific community viewed space-based solar power as technically fascinating but economically unsustainable. In 1968, a year before the moon landing, scientist Peter Glaser published a proposal in *Popular Science* for an inexhaustible source of clean energy: a massive solar panel in geosynchronous orbit that would capture sunlight and beam electricity to Earth. In the early 1970s—at the height of the oil crisis—the U.S. Department of Energy commissioned the first formal studies on the concept. They concluded the project was infeasible due to prohibitive launch and construction costs. Today, however, that context has changed radically.

 

 

Reduced costs and an industry revolution

Today, the economic equation of space launches has been fundamentally rewritten. The cost of reaching orbit has plummeted by nearly 90 percent compared to the last century; while a launch in the 1990s cost roughly $20,000 per kilogram, SpaceX’s reusable Falcon 9 has driven that price down to approximately $2,000. Simultaneously, satellite manufacturing has moved beyond the “artisanal” methods of previous decades toward a true industrial revolution. This new paradigm features automotive-style assembly lines, rapid iteration, and genuine mass production. Finally, the growing militarization of the Earth-Moon domain has turned space into an area of strategic confrontation, creating a context where the availability of massive, reliable energy is now a critical necessity.

These shifts explain why governments, space agencies, and private entrepreneurs are showing intense interest in the feasibility of SBSP. The operating principle is based on an energy conversion chain that is simple in theory but complex in practice: large photovoltaic panels are launched into orbit aboard stabilized satellites to collect continuous solar radiation, unfiltered by the atmosphere and unaffected by the day-night cycle. This electricity is converted into microwaves or lasers, beamed to Earth, and captured by antennas that feed the power back into the grid.

The primary advantage is the intensity of the source. In space, sunlight is about 30 percent stronger than at ground level. While solar irradiance on Earth peaks at around 1,000 watts per square meter, it remains a constant 1,400 watts in orbit, untouched by seasons, weather, or nightfall. In theory, a geostationary collection system could provide a nearly inexhaustible, constant flow of clean energy.

However, this apparent simplicity masks daunting engineering hurdles. To be economically viable, an orbiting power plant would need to be several kilometers wide—a scale far beyond that of the International Space Station. While modular construction and robotic assembly are promising, they remain experimental. Some researchers, including a team at Caltech, are exploring “swarm” architectures—coordinated groups of small panels—to avoid the risks of building a single, monolithic megastructure.

Caltech’s work is already yielding results. In 2023, the university successfully demonstrated the wireless transmission of solar energy from space to Earth for the first time. Their Space Solar Power Demonstrator (SSPD-1), launched aboard a Falcon rocket, featured three key systems: MAPLE, an array of flexible microwave transmitters; DOLCE, an ultralight foldable structure; and ALBA, a suite of 32 different types of photovoltaic cells.

While this success was symbolic rather than an immediate industrial breakthrough, it followed closely on the heels of a Pentagon experiment that paved the way. In 2020, the secretive X-37B military spaceplane carried the PRAM (Photovoltaic Radio-frequency Antenna Module) into orbit. Over a 30-month mission, PRAM successfully tested energy collection, allowing the Caltech team to take the next step: proving that a lightweight, deployable system could accurately target a receiver on the ground.

Beyond beaming power to Earth, the Caltech mission achieved another milestone: MAPLE successfully directed microwaves from one part of the satellite to another to light up two LEDs. Though the distance was less than half a meter, it was the first documented demonstration of energy transmission within space. This suggests a future where energy can be beamed not just to our planet, but to other satellites, orbiting stations, or even high-powered orbital data centers.

 

 

 

 

The idea of a space power bank in the future

The vision is to establish orbital power distribution hubs to recharge satellites, space stations, and deep-space probes, allowing them to operate longer and travel further. Future lunar bases or space-based internet constellations could utilize this infrastructure as a sort of “orbital power bank.”

This is precisely the vision pursued by China, which has made SBSP a strategic energy priority alongside the United States. The China Academy of Space Technology (CAST) is working on an ambitious project called Zhuri (“Chasing the Sun”). It envisions building a circular, kilometer-wide solar plant in geostationary orbit within the next two decades, capable of generating gigawatts of electricity. The project is being executed in stages, moving from low-Earth orbit tests to geostationary trials before final construction.

In Bishan, CAST has built a 75-meter test tower to simulate the wireless transmission process. They have already successfully sent energy from a single transmitter to multiple mobile receivers simultaneously. Current research focuses on beam accuracy and miniaturizing equipment to make it viable for space deployment. Meanwhile, the Tiangong Space Station, manned by taikonauts since 2021, serves as a vital testbed for the high-voltage systems and robotic assembly techniques required for these massive orbital arrays.

Other nations are following suit. Japan’s OHISAMA project aims to launch a demonstration satellite to test beaming 1 kW of power from orbit to ground stations. The European Space Agency (ESA) is pursuing the SOLARIS initiative, with a goal of building a 200-kW demonstrator within the decade, though these efforts remain in the preliminary study phase.

While early tests are promising, the decisive step will be the involvement of major utility companies. To date, SBSP has remained the domain of researchers and space agencies. Transforming it into actual infrastructure requires the business models, regulatory frameworks, and grid integration typical of the power industry.

Traditional utilities should be careful not to overlook the fact that entrepreneurs like Elon Musk and Jeff Bezos are already building the affordable launch systems needed to put these energy-hungry systems into orbit. Bezos, in particular, has been vocal about moving heavy, energy-intensive industry into space. These titans are unlikely to rely on energy sources controlled by others; in the long term, they could become the energy providers themselves.

The telecommunications sector offers a clear warning: in just a few years, Starlink has revolutionized global internet connectivity and is now challenging the mobile phone market. While many large European firms currently maintain a cautious “wait-and-see” approach due to cost uncertainties, no major player can afford to ignore a technology that—propelled by the momentum of Big Tech—could fundamentally redefine the global energy landscape.

 

 

Business must be ready for change

These are no longer science-fiction projects but a near-future reality fast approaching, and the history of space activity over the last two decades should serve as a warning.

In 2007, during a conference, a 36-year-old Elon Musk declared that SpaceX would crush the competition in space launches and dominate orbit. The audience laughed, and neither U.S. nor European aerospace companies took him seriously. Today, reusable Falcon rockets launch every two days from multiple sites, and 10,000 Starlink satellites orbit the Earth—a number expected to reach 30,000 by 2030.

No one is laughing anymore. Technology is advancing with incredible speed, and corporations cannot afford to ignore it. Space-based solar power could represent a major pillar of the future of energy, and major players must be careful not to miss the opportunity to lead this change.