China plans to build the ‘Three Gorges Dam’ in space

China announced an ambitious project to build a large-scale solar power plant in space with the support of super heavy rockets, Interesting Engineering reported on January 10. The man in charge of the project, senior rocket scientist Long Lehao, describes it as “another Three Gorges Dam project above Earth”. The Three Gorges Dam on the Yangtze River is the largest hydroelectric project on Earth with an annual electricity production capacity of about 100 billion kilowatt hours.

“Currently, we are working on this project. The project is as meaningful as bringing the Three Gorges Dam into geostationary orbit at an altitude of 36,000 km above the Earth,” said Lehao, a member of the Chinese Academy of Engineering. Quoc (CAE), shared in a lecture.

The key benefit of solar power generation in space is continuous operation, unhindered by weather, day-night cycles or seasonal fluctuations. Furthermore, the intensity of sunlight reaching a surface in space is much greater than on the ground. Long plans to install a kilometer-wide photovoltaic battery along the geostationary orbit. The energy collected in one year will be equivalent to the total amount of oil that can be extracted from the Earth. Placing the battery pack in geostationary orbit ensures it is fixed relative to Earth, optimizes exposure to sunlight and simplifies the task of transmitting energy to the ground.

The success of the solar power production project in space lies in the powerful rocket. Long and his colleagues are developing the Long March 9 (CZ-9), a reusable heavy-lift rocket. This giant rocket could lead the world in its ability to transport heavy cargo. With the capacity to carry more than 150 tons of cargo into orbit, it will surpass NASA’s most powerful rockets such as the Saturn V and the Space Launch System (SLS).

China is testing key technologies for the project. In June 2021, China started construction of an experimental space solar power plant in Bich Son. In November 2023, researchers at Xi’an University of Electrical Science and Technology announced the test results of “Chasing Sun Project”, the world’s first complete ground-based testing system for solar PV cosmic sky. The system demonstrates world-leading performance in microwave power transmission, beam acquisition performance and power transmission efficiency. However, Long’s project may take years to become a reality.

Companies such as Lockheed Martin and Northrop Grumman of the US are also actively developing space solar power production technology. The California Institute of Technology is also engaged in research and development of related technology.