The UK government is reportedly considering a £16 billion proposal to build a solar power station in space.
Yes, you read that right. Space-based solar power is one of the technologies to feature in the government’s Net Zero Innovation Portfolio.
It has been identified as a potential solution, alongside others, to help the UK achieve net zero by 2050.
But how would a solar power station in space work? What are the advantages and drawbacks to this technology?
Space-based solar power involves collecting solar energy in space and transferring it to Earth. While the idea itself is not new, recent technological advances have made this prospect more achievable.
The space-based solar power system involves a solar power satellite, an enormous spacecraft equipped with solar panels. These panels generate electricity, which is then wirelessly transmitted to Earth through high-frequency radio waves. A ground antenna, called a rectenna, is used to convert the radio waves into electricity, which is then delivered to the power grid.
A space-based solar power station in orbit is illuminated by the sun 24 hours a day and could therefore generate electricity continuously. This represents an advantage over terrestrial solar power systems (systems on Earth), which can produce electricity only during the day and depend on the weather.
With global energy demand projected to increase by nearly 50 percent by 2050, space-based solar power could be key to helping meet the growing demand on the world’s energy sector and tackling global temperature rise.
A space-based solar power station is based on a modular design, where a large number of solar modules are assembled by robots in orbit. Transporting all these elements into space is difficult, costly, and will take a toll on the environment.
The weight of solar panels was identified as an early challenge. But this has been addressed through the development of ultra-light solar cells (a solar panel comprises smaller solar cells).
Space-based solar power is deemed to be technically feasible primarily because of advances in key technologies, including lightweight solar cells, wireless power transmission, and space robotics.
Importantly, assembling even just one space-based solar power station will require many launches. Although space-based solar power is designed to reduce carbon emissions in the long run, there are significant emissions associated with space launches, as well as costs.
Rockets are not currently fully reusable, though companies like Space X are working on changing this. Being able to fully reuse launch systems would significantly reduce the overall cost of space-based solar power.
If we manage to successfully build a space-based solar power station, its operation faces several practical challenges, too. Solar panels could be damaged by space debris. Further, panels in space are not shielded by Earth’s atmosphere. Being exposed to more intense solar radiation means they will degrade faster than those on Earth, which will reduce the power they are able to generate.
The efficiency of wireless power transmission is another issue. Transmitting energy across large distances (in this case from a solar satellite in space to the ground) is difficult. Based on the current technology, only a small fraction of collected solar energy would reach the Earth.