A kilometer-long solar power plant in space? This Chinese project is monumental 🛰️

A solar power plant, floating 22,370 miles (36,000 km) above Earth, might seem like science fiction. Yet, China is actively working to bring this project to life, which could transform our energy supply.

This project, comparable in scale to the Three Gorges Dam, aims to harness solar energy in space, where sunlight is ten times more intense than on Earth. The goal is to produce, in one year, an amount of energy equivalent to the world's oil reserves. Indeed, the announced production would be 100 billion kilowatt-hours annually.

An extraordinary solar power plant

The Chinese space-based solar power plant, with a width of 0.62 miles (1 kilometer), would be assembled in geostationary orbit. This position would allow for continuous energy production, without interruptions due to day-night cycles or weather conditions. The collected energy would then be transmitted to Earth in the form of microwaves.

This system eliminates the limitations of terrestrial solar power plants, such as intermittent production or dust accumulation on panels. According to Chinese scientists, this technology could provide a nearly limitless energy source.

A colossal technological endeavor

The construction of such a power plant would require dozens, if not hundreds, of launches to transport components into orbit. China is relying on its Long March-9 rocket, capable of carrying up to 165 tons (150 metric tons), to meet this challenge. This reusable rocket would reduce costs and the number of missions needed.

However, technical obstacles remain, particularly the efficient transmission of energy to Earth. Significant losses could occur during the conversion of microwaves into usable electricity. Tests, such as those conducted by Caltech in 2023, show that this technology is promising, nonetheless.

A project with geopolitical implications

China is not the only country interested in space-based solar energy. The United States, Japan, and Europe are also exploring this avenue. These projects could redefine global energy balances by offering a non-carbon-based and abundant energy source.

For China, this project is part of a broader strategy to strengthen its technological and energy positioning. It is also a step forward in decarbonization, a major goal in the face of the climate emergency.