China Makes Space Solar Power Strategic Plan

China has formally included a space solar power station initiative in its 15th Five-Year Plan. This marks a strategic shift from conceptual research to engineering pre-development for space-based energy infrastructure.

Credit: PANDAILY

The plan's reference to space solar power, though brief, carries significant weight. It represents a directional advance deployment, exploring long-term energy solutions beyond 2050 at the national planning level. The space solar power station concept involves collecting solar energy in geostationary orbit. Sunlight there is available constantly, at roughly 10 times terrestrial intensity, then transmitted to Earth via microwave or laser beams.

And three technology pathways are now progressing towards engineering validation. The first concerns energy materials. This involves ultra-high-efficiency solar cells capable of withstanding the space radiation environment. Gallium arsenide cells remain a mainstream solution, offering over 30 per cent conversion efficiency. Crystalline silicon and emerging perovskite thin-film technologies present promising cost-reduction paths. China's substantial manufacturing capacity, over 90 per cent of global silicon photovoltaic production, offers a distinct industrial basis.

The second pathway focuses on wireless power transmission. Professor Duan Baoyan's "Zhuri Project" established the world's first full-chain ground verification system for space solar power stations. This system achieved kilowatt-level power output over distances of hundreds of metres, utilising dynamic target microwave transmission. Professor Yang Shizhong's team has also pursued stratospheric power generation, alongside both microwave and laser wireless transmission methods.

So additional teams are also contributing to this area. These include groups at the China Academy of Space Technology, the Institute of Electrical Engineering at CAS, Beijing Institute of Technology, and Harbin Institute of Technology. These organisations are advancing high-power microwave transmission and space power systems. The third pathway addresses space infrastructure and in-orbit assembly.

A single gigawatt-class geostationary space solar station could weigh thousands of tonnes. This mass is tens to hundreds of times greater than the International Space Station's 420-tonne mass. Breakthroughs in reusable launch vehicles, such as the Long March 9, are considered critical. Modular in-orbit assembly and space robotics are also bringing these large scales into economic consideration.

But the commercial space industry has seen rapid development. This has significantly reduced launch costs. The financial viability of space-based power generation is now more frequently considered. Companies including Star Energy Power and Stellar Power have emerged as early movers in space-grade photovoltaic materials.

Perovskite cells developed by these companies have undergone in-orbit validation aboard commercial satellites and the China Space Station. These cells have accumulated months of real-space environment performance data. Such data is essential for long-duration service validation, according to Pandaily.com.

• China's space solar power initiative is now part of its 15th Five-Year Plan.

• This signals a move from theoretical research to engineering pre-development.

• Three key technical pathways are being developed: energy materials, wireless power transmission, and orbital infrastructure.

• Industry entities are conducting in-orbit validation for critical photovoltaic materials.

Source: Pandaily