China’s space solar project has been dubbed the Manhattan Project of the energy sector—a reference to the top-secret World War II program that developed the first atomic bombs. The scale of ambition here is monumental, with the potential to reshape global energy production.
“We are working on this project now,” says Long Lehao, a senior Chinese scientist and member of the Chinese Academy of Engineering, who is one of the key figures behind the project.
“It is as significant as moving the Three Gorges Dam to a geostationary orbit 36,000 km above the Earth. This is an incredible project to look forward to.”
Long Lehao revealed further details of the project during a lecture at the Chinese Academy of Sciences (CAS) in October, with his speech transcription later released by the academy in December.
What is China’s Three Gorges Dam?
While space ventures promise enormous potential for the future, China already operates the world’s largest hydropower project—the Three Gorges Dam. Situated on the Yangtze River, this colossal feat of engineering took 17 years to complete and generates approximately 100 billion kWh of electricity annually.
The dam, an investment of $25-$35 billion, demonstrates China’s prowess in large-scale energy projects. Beyond power generation, the Three Gorges Dam also contributes significantly to flood control and river navigation, underscoring the multiple benefits of such monumental infrastructure.
The vision: A solar powerhouse in geostationary orbit
China’s plan to deploy a 1km-wide solar array 36,000 km above Earth isn’t just ambitious—it’s a potential game-changer for space-based solar power (SBSP). By escaping atmospheric interference, the array could generate six times more energy than terrestrial solar farms, with uninterrupted exposure to sunlight. The project, likened to a cosmic-scale Three Gorges Dam, aims to convert sunlight into microwaves and beam them to Earth, where receivers would feed the grid.
Why geostationary orbit? At this altitude, the array remains fixed relative to Earth, ensuring consistent energy transmission. Early estimates suggest it could harvest as much energy in a year as the planet’s recoverable oil reserves—a staggering claim that underscores SBSP’s disruptive potential.
The tech: From sci-fi to reality
Space-based solar power relies on three pillars:
- Orbital solar farms: Ultra-lightweight, modular panels resistant to radiation.
- Wireless power transmission: Microwaves or lasers beam energy to ground stations with minimal loss.
- Ground infrastructure: Rectennas (rectifying antennas) convert microwaves into electricity.
China isn’t alone. The UK’s Space Solar recently achieved 360° wireless transmission, a critical step. Meanwhile, Japan’s JAXA and the U.S. Space Force are exploring SBSP for military and civilian use. But China’s state-backed approach—combining expertise from its space program and renewable energy sector—gives it a unique edge.
The challenges: Cost, physics, and politics despite the promise, space-based solar power faces hurdles:
- Launch costs: Deploying a 1km structure requires hundreds of SpaceX-class launches. Even with reusable rockets, estimates suggest costs could exceed $10 billion—comparable to building a nuclear power plant.
- Efficiency losses: Microwave transmission loses ~50% of energy in transit. Increasing efficiency is key to economic viability.
- Orbital debris: A structure this size risks collisions, demanding advanced debris mitigation.
- Geopolitical tensions: Beaming microwaves across borders may spark security concerns and regulatory hurdles.
Yet, advocates argue SBSP’s scalability and 24/7 output justify the investment. As solar panel efficiency improves and launch costs drop—potentially to $100/kg by 2040—the economics could shift dramatically, making SBSP competitive with nuclear and even fossil fuels.
The global race
Who leads the SBSP frontier? China’s project is the most advanced, but competitors are close:
- U.S.: Caltech’s MAPLE experiment proved wireless transmission in 2023.
- UK: Space Solar aims for a demo by 2035, backed by government funding.
- Japan: JAXA plans a 1GW orbital farm by 2050.
China’s lead stems from its centralized planning and existing mega-infrastructure (e.g., Three Gorges Dam). If successful, it could dominate the space energy market, much like it leads in terrestrial solar.
A new dawn for renewable energy?
Space-based solar power is no longer fantasy—it’s a strategic priority. If SBSP reaches even half its projected potential, it could revolutionize global energy, challenging fossil fuels and even terrestrial renewables. The next decade will determine whether this cosmic ambition becomes Earth’s next energy revolution or remains an expensive dream.