A terrestrial prototype is testing energy transmission by microwaves.
XI’AN, China | June 2026
Chinese researchers are developing a space-based solar power plant designed to collect sunlight in geostationary orbit and transmit electricity wirelessly across more than 36,000 kilometers to Earth. The project, known as Zhuri, or “chasing the sun,” is being led by scientists at Xidian University in Xi’an. Its long-term objective is to create orbital stations capable of delivering continuous clean energy without being interrupted by night, clouds or atmospheric conditions. The concept remains experimental, but a ground-based prototype has already demonstrated several of its essential technologies.
The university’s test facility uses a 4.8-meter parabolic mirror suspended from a 75-meter tower. The mirror concentrates sunlight onto photovoltaic panels that generate electricity before the energy is converted into microwaves. Those microwaves are transmitted across approximately 100 meters to a receiving antenna known as a rectenna. The rectenna then converts the electromagnetic signal back into usable electrical power.
Recent trials reached kilowatt-level energy transmission and demonstrated the ability to direct power toward several moving targets simultaneously. A group of specialists validated the results, identifying them as an important step in proving that solar energy can be collected, converted and transmitted through a controlled wireless system. The experiment does not reproduce the immense distance of an orbital transmission, but it tests the same three-stage process required for a future space station. Those stages are light concentration, conversion into microwaves and final rectification at the receiving point.
The team is also testing Fresnel lenses measuring between two and seven meters wide. These lightweight optical systems can focus sunlight while using less material than conventional solid lenses, an important advantage for structures that may eventually be launched into space. Cooling fluids are being incorporated to control the high temperatures produced during solar concentration and energy conversion. Thermal management will be essential because excessive heat can reduce efficiency and damage sensitive components.
Space-based solar power offers several theoretical advantages over conventional solar farms. In geostationary orbit, a station could receive nearly constant sunlight and avoid the daily cycle that limits terrestrial panels. It would also operate above clouds, storms and the filtering effects of Earth’s atmosphere. Researchers involved in the project estimate that solar energy density in space can reach several times the level available at the planet’s surface.
The ability to generate energy continuously could address one of the main weaknesses of renewable electricity. Ground-based solar and wind systems depend on weather conditions and often require batteries or backup generation to maintain stable supply. An orbital plant could theoretically send power whenever demand increases, provided that the transmission beam remains precisely aligned with its receiving station. That reliability is why researchers view the concept as a possible contribution to future global energy security.
Duan Baoyan, an electromechanical engineer and former president of Xidian University, directs the broader vision behind the program. His work draws inspiration from space solar power concepts developed internationally, including NASA’s SPS-ALPHA proposal. Duan imagines stations capable of supplying electricity to entire cities rather than only supporting specialized space operations. A one-gigawatt installation, comparable to a medium-sized power plant, would require mirrors extending hundreds of meters.
Constructing such a system presents enormous engineering challenges. Launching a single structure of that scale would be prohibitively complex and expensive with existing technology. The Zhuri design therefore favors independent modules flying in formation instead of one massive platform. This approach could improve resilience, simplify maintenance and allow damaged sections to be replaced without disabling the entire station.
Formation flying would also allow the plant to expand gradually. Additional modules could be launched as funding, manufacturing capacity and orbital infrastructure improve. However, every unit would need to maintain extremely accurate positioning so that the combined microwave beam remained stable. Small navigation errors across tens of thousands of kilometers could reduce efficiency or direct energy away from the intended receiver.
Beam safety is one of the project’s most sensitive issues. Engineers must guarantee that microwave transmission does not endanger aircraft, satellites, wildlife or people near the receiving area. The energy density would need to remain within controlled limits while still delivering commercially useful electricity. Automated shutdown systems and continuous tracking would be required if an object entered the transmission path.
The receiving infrastructure on Earth would also be substantial. Rectenna fields could occupy large areas because microwave beams spread over distance and must be captured efficiently. Unlike conventional solar farms, these installations would not require direct sunlight, allowing them to operate during nighttime or poor weather. Their location would nevertheless need to account for population density, aviation routes, environmental effects and access to national power grids.
The economic challenge may be even greater than the scientific one. Space solar power requires advanced launch systems, lightweight materials, robotic assembly and highly reliable components capable of operating for years without conventional maintenance. Falling launch costs could improve feasibility, but the initial investment would remain enormous. The technology must eventually compete with increasingly affordable terrestrial solar panels, wind power, batteries and nuclear generation.
Shorter-term applications may arrive before a city-scale power plant becomes realistic. Wireless energy transmission could recharge satellites in orbit, extending their operational lives without requiring larger onboard solar arrays. Similar systems could provide electricity to lunar bases from orbit or from installations located elsewhere on the Moon. These uses involve shorter distances and smaller power requirements than transmitting energy to Earth.
The Xidian University team now hopes to secure funding for orbital experiments. A successful demonstration in space would test how the system performs in vacuum, extreme temperatures and continuous radiation exposure. It would also provide data on alignment, conversion losses and beam control over much greater distances. Without those experiments, the project will remain a promising terrestrial prototype rather than an operational energy system.
Zhuri represents an ambitious attempt to move electricity generation beyond the limits of Earth’s surface. Its prototype has shown that sunlight can be concentrated, transformed into microwaves and transmitted wirelessly at useful power levels. The leap from 100 meters to more than 36,000 kilometers remains vast, but every orbital energy network must begin with controlled experiments on the ground. If the engineering and economic barriers can be overcome, the Sun could eventually supply continuous power from far above the atmosphere.
The future begins where distance stops being a barrier. / El futuro comienza donde la distancia deja de ser una barrera.