The idea of putting solar farms in space to supply the earth is not new: it was first imagined by the pioneering Russian scientist Konstantin Tsiolkovsky in the 1920s, decades before space launches or satellites.
Japan has been studying the technology since the 1980s, when scientists at Kyoto University started to crack one of the key challenges of transmitting power over long distances by flying an aeroplane powered with microwave energy.
But a combination of cheaper solar panels, initiatives to solve the climate crisis, developments in robotics and – crucially – cheaper space launches, have started to make the idea seem viable, even competitive with terrestrial energy generation.
The cost of solar cells has fallen by 85pc in the last decade and the cost of putting a satellite in space, thanks to reusable rockets from Elon Musk’s SpaceX, has been on a similar downward spiral. The amount needed to put a kilogram in space sat at almost $20,000 (£14,670) between 1970 and 2000. Since then it has moved closer to $2,000.
“What SpaceX are doing with Starship [the company’s forthcoming heavy rocket], and the economics of that, what Elon Musk is proposing, is transformative,” says Sam Adlen, head of business innovation for the Satellite Applications Catapult, an organisation to boost space research in the UK. “We’ve seen in the last 5-10 years a revolution in space. We’re talking about things that were science fiction 10 years ago.”
Nonetheless, drawing solar power from space would be a gargantuan engineering challenge. The Government-commissioned report, authored by Frazer-Nash and delivered last month, proposes a 1,700-metre wide structure – more than double the height of the Burj Khalifa in Dubai, the world’s tallest building. It would weigh 2,000 tonnes, or roughly six Boeing jets, and orbit the earth at 35,000 km.
Impossible to launch in one piece, the system would instead be sent into space in thousands of “modular” pieces, the size of a desktop computer, that would be slotted together in space by robots.