Building the solar power farm in space would take more than 60 rocket flights and a team of robot builders, but it’s one step closer to becoming a reality.
A company hoping to launch the first solar farm into space has passed a critical milestone with a prototype on Earth.
Oxfordshire-based Space Solar plans to power more than a million homes by the 2030s with a mile-wide complex of mirrors and solar panels orbiting 22,000 miles above the planet.
But its super-efficient design for harvesting constant sunlight, called CASSIOPeiA, requires the system to rotate towards the sun, whatever its position, while still sending power to a fixed receiver on the ground.
That’s now been shown to work for the first time at Queen’s University Belfast, with a wireless beam successfully “steered” across a lab to turn on a light.
Martin Soltau, the company’s founder, said, “This is a world-first. You can get constant energy all the time.
“This is really going to have a substantial impact on our future energy systems.”
Solar panels capture 13 times more energy in space than they do on the ground because the light intensity is higher and there’s no atmosphere, clouds, or night.
Even though some energy would be lost by the time it was beamed back to Earth and connected to the electricity grid, it would still far outstrip solar generation on the ground.
But it’s the production of power around the clock that makes space-based solar energy so attractive for providing a “baseload” to back up ground-based renewables.
Currently, nuclear energy and gas turbines provide the baseload for the grid but produce radioactive waste or carbon dioxide, respectively.
“This is why the government is so excited by the prospect of space-based solar power,” said Mr. Soltau.
“Not only is it very capable in that it’s helping to make the whole energy system work more effectively,.
“But the cost (of electricity) is about quarter of that from nuclear.”