Putting solar panels in space means you can collect the sun’s rays regardless of the weather, and, proponents say, it can help power remote parts of the world where infrastructure may not exist.
The technology is advancing:
Why We Wrote This
Solar panels in space have potential to bring power to remote locations or to areas hit by natural disaster. Private companies and others are working to refine the technology.
Space Solar, a British startup, envisions supplying enough solar power for around 3,000 homes by 2030.
A California-based startup says it will launch a constellation of orbiting mirrors by 2025 to extend hours of sunshine to solar panels on Earth.
And last year, a prototype from the California Institute of Technology gathered, for the first time, energy beamed back from space. China and Japan plan to follow suit – by 2028 and 2025, respectively.
Energy captured in space would be converted to radio waves (or lasers) and beamed to a receiving station on Earth, to be converted into electricity. Or, the hardware would act as giant mirrors, reflecting the sun’s rays to solar panels on the planet’s surface before the sun hits them directly in the mornings, or deep into dusk.
Cost is a hurdle: A recent NASA report found that space-based solar could be 12 to 80 times more expensive than terrestrial alternatives. But a recent test flight of SpaceX’s Starship showed promise that could bring the cost down.
Picture a vast field of solar panels, ranging in an unbroken array across nearly a square mile of land. Now shift that image into outer space, with the giant structure sitting tens of thousands of miles above Earth’s surface, and you have a sense of what space-based solar power seeks to achieve.
The drive for this energy source comes not just from its advantages over land-based solar, but also from characteristics that set it apart from most other energy sources.
Proponents say it can help power parts of the world that struggle to tap into more traditional forms of energy – either because of their remote location, or because the related infrastructure simply doesn’t exist.
Why We Wrote This
Solar panels in space have potential to bring power to remote locations or to areas hit by natural disaster. Private companies and others are working to refine the technology.
“Solar, fusion, nuclear, coal – you name it – you have to have a plant somewhere and provide infrastructure to support it,” says Paul Jaffe, a former electronics engineer at the U.S. Naval Research Laboratory. “With space solar, you have potential to redirect the energy from a satellite to anywhere on Earth.”
Technology is advancing
In a sign that the technology is stepping beyond the realm of science fiction, Space Solar, a British startup, recently penned a world-first partnership with an Icelandic energy company to supply solar power from space by 2030 – envisioning satellites sufficient to power around 3,000 homes.
Space Solar has also blazed past another milestone in being the first to demonstrate 360-degree power beaming technology – meaning solar panels can beam energy back to Earth, no matter how they rotate to continue facing the sun.
A California-based startup, meanwhile, says it will launch a constellation of orbiting mirrors by 2025 to extend the hours of available sunshine to solar panels on Earth.
And last year, a prototype from the California Institute of Technology gathered solar energy in space and beamed back a detectable amount for the first time. China and Japan have plans to follow suit – by 2028 and 2025, respectively.
“I’m very optimistic indeed,” says Martin Soltau, co-CEO and co-founder of Space Solar. “There are much more complicated robotics in space at the moment, like the Mars rover – we don’t need anything near as complicated as that.”
The idea of space-based solar is to harvest the sun’s energy far beyond the vagaries of our planet’s weather systems, and so high up that the solar panels’ view of the sun is almost never eclipsed.
The energy captured by these solar arrays would be converted to radio waves (or, in some cases, lasers) and beamed to a receiving station on Earth, using a concept of wireless power transmission, where the radio waves would, in turn, be converted into electricity.
In some versions, the hardware would simply act as giant mirrors, reflecting the sun’s rays down to solar panels on the planet’s surface, allowing them to convert energy into electricity before the sun hits them directly in the mornings, or deep into dusk.
These sunlight-harvesting structures would be incomparable in scale to anything currently in orbit: 3,000 times the area of the International Space Station, according to a NASA study of representative designs.
Cost is the biggest hurdle. Indeed, the NASA report found that space-based solar could be 12 to 80 times more expensive than terrestrial alternatives. But the report says it had to make assumptions because the technology is so new.
“We found that cost is really dominated by launch and manufacturing,” says Erica Rodgers, director of advanced programs for NASA’s Office of Technology, Policy, and Strategy, and lead author of the report.
