the space race for zero-carbon energy solutions

context: Space is becoming a key frontier in the global energy transition, offering the possibility of near-limitless clean energy for Earth and power for deep-space exploration. Yet alongside major technical challenges, unresolved questions around international regulation remain. As nations compete to develop space-based energy generation and transmission technologies, a new 'space race' is quietly unfolding.

Beyond Earth's atmosphere, solar radiation is stable and unaffected by day-night cycles or weather conditions, says Chai Qimin 柴麒敏 National Centre for Climate Change Strategy and International Cooperation strategic planning director. Nuclear fuel resources are abundant and can produce nearly inexhaustible clean energy. With rapid advances across multiple fields, it is increasingly viewed as a solution to the global energy dilemma, he argues. 

Chai outlines the current state of space-based zero-carbon energy

  • core concepts and principles of space-based zero-carbon energy 
    • space-based solar power stations (mainstream and most mature technology) 
      • core idea is to capture solar energy through large PV arrays, convert it to electricity and then transmit it to Earth or to space-based terminals 
      • at the receiving end, energy is converted and integrated into power grids, supplying clean electricity
    • space-based nuclear power stations (zero-carbon attributes depend on the technology route; currently in R&D phase) 
      • generate energy through nuclear reactions without emitting greenhouse gases, suited for deep-space exploration and supplying remote space facilities 
      • two main technical pathways 
        • space nuclear fission power stations (relatively mature) 
        • space nuclear fusion power stations (frontier) 
    • frontier technologies behind space zero-carbon energy 
      • photovoltaic cells and mega-arrays 
        • a 1GW space power station requires PV arrays up to 2m long: far beyond the capacity of any single launch, making in-orbit assembly essential 
        • solutions include
          • lightweight structural design using advanced materials 
          • robotic autonomous assembly in microgravity 
          • development of reusable launch vehicles 
          • reuseable rockets 
      • wireless power transmission 
        • once power is generated in space, transmitting it efficiently and safely to Earth becomes the central challenge 
        • wireless transmission provides the solution through microwave and laser based approaches 
        • microwave transmission is currently the mainstream option as it avoids interference with communication, offers low transmission losses and low accuracy requirements 
        • laser transmission offers extrenely high power density and compact antenna sizes, making it suitable for small payloads, satellite power transfer and low orbit applications 
          • it remains highly susceptible to atmospheric interference such as clouds and haze 
      • strategic choices 
        • orbit selection 
          • geostationary orbit (GEO) offers near continuous sunlight and stable earth coverage, ideal for GW scale stations, but it has high launch and assembly costs 
        • low earth orbit (LEO) offers lower costs and flexibility but suffers from intermittent sunlight 
        • the PRC and Japan favour GEO for large-scale deployment, other countries explore LEO for distributed systems 
  • national strategies in space zero-carbon energy 
    • Japan: a 40-year pioneer facing cost and timeline challenges
    • US: an innovator leveraging commercialisation and cost reduction 
    • EU: collaborative follower focused on tech R&D
    • the PRC: latecomer with rapid advances through its 'Chasing the Sun' program 
  • capital opportunities 
    • key investment tracks include
      • launch and in-orbit services
      • energy conversion and wireless transmission equipment
      • ground reception and smart grid integration 
    • high costs, safety concerns and regulatory uncertainty remain significant risks 

Chai notes 

  • tech trends point toward lightweight materials, intelligent autonomous systems and large-scale deployment
  • zero-carbon energy will integrate deeply with the space economy, supporting factories, satellite constellations and deep space exploration