The future of renewable energy? Giant mirrors hung in space
Thousands of giant mirrors could be placed in space to reflect sunlight onto solar farms.
The European Space Agency (Esa) is exploring the concept of direct sun reflection (DSR) – a technique in which sunlight would be bounced back down to Earth at dawn and dusk.
By focusing the light on pre-existing solar farms, the technique would add two hours of bright sunshine each day and boost output by 60 per cent, experts have calculated.
The idea is the brainchild of Brussels-based company Arthur D. Little (ADL) which is proposing placing 4,000 mirrors in space which will direct sunlight onto about 30 large solar farms.
It has been selected by Esa as one of two concepts that it is exploring as part of its Solaris initiative, which is looking at ways to exploit solar power from space.
Dr Sanjay Vijendran, Esa’s lead for Solaris, said: “We have been pleasantly surprised by the promise of this technology as a way of getting energy down from space.
“We think at Esa that there is a place in the future for this concept. It doesn’t need to be so efficient because the sun doesn’t charge you for the energy.”
Fully operational by 2043
ADL is hoping that the first proof-of-concept mirror could be launched into orbit in 2025, with commercially viable operations starting in 2033, and a full-scale suite of mirrors in place and fully operational by 2043.
Each mirror would be about 1km (0.6 miles) in diameter and could provide as much energy as peak daylight at noon.
Arnaud Siraudin, head of ADL’s technology and innovation practice in France, said: “Solar power only works when the sun is shining and high in the sky. This means panels are lying dormant about half of the time.
“We ask ourselves this question. How can we best exploit the huge financial and material investments being made into these farms? It is now possible to deliver clean energy from space through the concept of direct sun reflection.
“Within two years of the start of the project it will be possible to launch a small scale mirror to demonstrate the feasibility of the concept and by 2043, DSR will be fully operational.”
ADL was one of the first companies to suggest solar power from space in the 1970s after it was pioneered by employee Peter Glaser.
Britain is also keen to exploit solar power from space and is investing in several projects that could see energy being collected on giant panels before being beamed to earth through Wi-Fi.
Amanda Solloway, the minister for affordability and skills, said that the Government was committed to developing space-based energy.
‘Incredibly exciting’
“This technology has the potential to transform our power supply and that’s why it’s just so incredibly exciting,” she said.
“And I can tell you personally, our department and the Government are determined to make sure that we get the full potential of space solar in the future energy mix. That’s a real guarantee.
“My department is trying to build a secure energy supply for when the wind doesn’t blow and the sun doesn’t shine, and that is why space solar is such a fantastic opportunity and this is why we need to pursue it.”
In 1993, the Soviet Union, launched an orbital space mirror under the Znamya project with the intention of beaming solar power to Earth through reflected sunlight.
The mirror produced a three-mile-wide bright spot which moved through southern France to western Russia at a speed of about five miles a second and which was reported as looking like a flash of light by several onlookers. It was deorbited after just a few hour. A second attempt was made in 1999, but when that failed the project was cancelled.