Edith Mao

Published: 11:00pm, 16 Aug 2025

China has been urged to speed up the development of solar power in space to gain a stronger footing in the new energy sector and the space race.

Ge Changchun, an academician at the Chinese Academy of Sciences, called in an article for a top-down strategy to speed up efforts to develop the technology and narrow the gap with the United States in sectors such as materials and precision control.

Space solar power facilities are designed to be built and operated in orbit, where they convert solar energy directly into electricity before transmitting the power to Earth via microwaves or lasers.

Unlike ground-based solar plants, space stations are not affected by the weather or nightfall. Solar radiation in space is also far more intense than on Earth, making the technology a more efficient way of continuously generating power.

China’s research in this field relies primarily on efforts by universities and research institutions, but Ge wrote in an article for China Science Daily that they “lack the capacity to support such a vast, complex systems project”.

Compared with the United States, which conducted solar energy transmission experiments as early as the 1970s, China was relatively late in developing space solar power.

The sector was first added to the national preliminary research programme in 2008, and in 2021 the country started building its first space solar power research facility in Chongqing.

The project involves a 2.6 billion yuan (US$362.2 million) investment and is expected to have completed a small stratospheric pilot facility by the end of this year.

China is aiming to finish the experimental verification process before 2030 and to develop the technology for commercial use by 2050, according to Ge.

But he warned that the country still faced a “notable gap” compared with other developed nations, particularly with regard to project costs, material lifespan and maintenance technology.

“For example, China’s [rocket] launch costs stand at approximately US$2,000 per pound, nearly 40 per cent higher than SpaceX in the US. This constrains the feasibility of large-scale orbital deployments,” he said.

“China’s on-orbit servicing technology remains at the ground testing phase, while the US has conducted robotic autonomous repair trials.

“Moreover, critical materials used by China lag over 50 per cent behind US and Japanese equivalents in lifespan, directly impacting power stations’ long-term operational efficiency and economic viability.”

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Ge wrote that building extra-large space structures demanded materials with exceptional strength, weight efficiency and thermal protection, which required advances in critical materials technology and core components.

He added that high-power wireless transmission efficiency must be increased from the current level of 50 per cent to at least 60 per cent.

The article also argued that the country needed to develop its systems integration and operational experience for large-scale space solar power projects, suggesting it should “build small space power stations first, then gradually assemble them into larger systems [for] greater flexibility and simpler verification and implementation”.

He also said there was a need for better monitoring and protection to prevent space debris from damaging solar installations.

Other countries working on space solar power include the US and Japan.

The US Air Force Research Laboratory plans to conduct a wireless power transmission experiment this year, using a satellite’s solar panels to generate electricity and transmit it to low-Earth orbit as microwave radiation, simulating space-based solar power generation.

Last December, Japan successfully tested a high-altitude vehicle that sent microwaves to a ground receiver from a height of 7,000 metres (about 23,000 feet).

Edith Mao

Edith is an undergraduate student at the Hong Kong Baptist University, majoring in international journalism. Her interests lie in society, culture and the environment.