Beaming electricity all the way down to Earth from solar panels in space has been a clean energy dream for a long time. Although the technology still has a protracted approach to go before it will probably keep the lights on at home, there’s more hype than ever that space-based solar energy stations could actually work.
A significant milestone was announced this month when researchers at Caltech said that a prototype launched into space was in a position to beam a small amount of power to Earth. It was a vital first for the nascent technology, and other researchers all over the world are racing to make similar progress with funding from governments trying to succeed in their climate goals.
“I actually have a tough time not letting my imagination run wild after I start this.”
In space, solar panels can take in unfiltered sunlight across the clock with no setting sun. They could have the ability to generate as much as eight times as much electricity as land-based solar panels, in line with Caltech. The hope is that we’d have the ability to someday harness that abundant clean energy here on Earth or potentially even outposts on the Moon.
“I actually have a tough time not letting my imagination run wild after I start this. It has an odd seductiveness like that,” Nikolai Joseph, a senior technology analyst at NASA Goddard Space Flight Center, tells .
How feasible it’s to show those dreams into reality anytime soon is the topic of a study Joseph is working on with colleagues for NASA. Caltech’s demonstration was a game-changer, he says. “If you happen to’d asked me if that was going to occur a yr ago, I’d have said, ‘Oh no, probably not.’ After which they simply did it, which is wild,” he says. Joseph compares the milestone to a serious breakthrough in nuclear fusion that made headlines last yr.
Caltech showed that it could overcome one among the trickiest engineering challenges with space-based solar energy: how you can safely send electricity zooming from space all the way down to Earth. A SpaceX rocket launched a spacecraft carrying Caltech’s prototype into space in January. The prototype includes solar cells and an array of transmitters that may beam energy to different locations. The photovoltaic cells convert sunlight into electricity, which then must be converted into microwaves so it will probably be transmitted wirelessly. (Caltech has a neat video explainer.)
A number of months after launch, Caltech’s prototype was in a position to beam some power through space and ultimately back to the university. It began small, sending microwaves to receiver arrays a couple of foot away from the transmitter. The receiver arrays were in a position to convert the microwaves back to direct current (DC) electricity and use that to light up a few LEDs. The prototype also beamed a “detectable” amount of power all the way down to a receiver on the rooftop of a Caltech lab in Pasadena, California.
“We had, after all, tested it on Earth, but now we all know that it will probably survive the trip to space and operate there,” Ali Hajimiri, a professor of electrical and medical engineering who led the Caltech team, said in a press announcement. “To the perfect of our knowledge, nobody has ever demonstrated wireless energy transfer in space even with expensive rigid structures. We’re doing it with flexible lightweight structures and with our own integrated circuits. This can be a first.”
And it’s looking prefer it may not be the last. Earlier this week, the UK announced £4.3 million in government funding for several research initiatives. That features a group at Queen Mary University of London developing its own wireless system for beaming microwave energy from place to position. And the US Naval Research Laboratory launched an experiment to the International Space Station earlier this yr with the goal of beaming power across space using laser transmitters.
Although research is ramping up now, the primary patent for space-based solar energy was filed in 1968 by aerospace engineer Peter Glaser. NASA and the Department of Energy took an interest within the concept within the Nineteen Seventies because the world faced an energy crisis. But it surely was ultimately deemed too expensive to pursue the concept.
“The price is the massive issue.”
Even today, “The price is the massive issue,” says Xiaodong Chen, a professor of microwave engineering at Queen Mary University of London. “You’re constructing such big infrastructure in space.”
The economics are starting to alter, though, with the business space industry driving down launch costs. Probably the most ambitious timeline to this point is for this technology to be able to power homes and businesses on Earth by 2050, Chen says.
By 2050, in an effort to meet climate goals set within the Paris agreement, greenhouse gas emissions have to reach net zero. There’s no likelihood of hitting that goal overnight. So space-based solar shouldn’t be seen as a competitor to Earth-bound solar farms, says a 2022 report on the technology by the European Space Agency. The world needs as much renewable energy as it will probably get, as soon as it will probably get it.