The Current - Could solar power from space actually work?

Episode Date: May 12, 2026

It sounds like something straight out of science fiction: giant solar panels floating in space, beaming energy back down to Earth. Companies like Meta and space agencies in Japan are taking the idea seriously, hoping it could help power growing energy demands. Supporters say space-based solar could deliver constant, around-the-clock clean energy because the sun never stops shining. Critics say the technology is wildly expensive and still far from reality. Matt Galloway speaks with former NASA physicist John C. Mankins and former NASA technology policy chief Charity Weeden about whether this is the future of energy or a very expensive fantasy.

You know that feeling when you reach the end of a really good true crime series? You want to know more, more about the people involved, where the case is now, and what it's like behind the scenes. I get that. I'm Kathleen Goldhar and on my podcast Crime Story, I speak with the leading storytellers of true crime to dig deeper into the cases we all just can't stop thinking about. Find crime story wherever you get your podcasts. This is a CBC podcast. Hello, I'm Matt Galloway, and this is the current podcast. This is a breakthrough that could make clean power, reliable, and affordable everywhere.

Rather than building power plants all over the world, we're going to build the power plants up in space. We're creating space energy for Earth to power the grid with limitless, continuous energy. Limitless, continuous energy. Sounds like something out of science fiction. In fact, Isaac Asimov did write a short story about space solar power back in the 19th. But this company that put that ad together, Overview Energy, is real. And it just signed a giant deal with Meta to build a solar farm in space. Scientists to Caltech have proven that space-based solar farm is actually possible. They did a test back in 2023.

And Japan's space agency is also planning experiments to transmit solar energy from outer space. John C. Mankins is a former NASA physicist and longtime advocate for space-based solar power, John, good morning. Good morning. It's a pleasure. Good to have you here. What excites you the most about the prospect of harvesting solar energy in space? Probably the tremendous amount of progress that's been made over the last 10 years on many technological fronts towards the realization of this vision. Walk us through what the vision means and how it works. I think obviously people are familiar with solar panels, but how do you get what the solar panels would collect down to Earth and running data centers here if they exist

up in outer space. So at a functional level, the idea is extremely simple. You put a large platform in space, very much like a communication satellite, but much larger and much lighter in weight. You harvest the sunlight, turn it into electricity, turn the electricity into a wireless powered transmission, usually in microwave, but sometimes in a higher frequency like laser, you send it to a receiver on the earth where it's converted back into electricity and then distributed to the grid, just as you do with utility scale ground-based solar.

That sounds very simple, but it's obviously not simple at all. Let's talk about the scale of things. What would you need to be able to pull this off at scale? So space solar power, or rather, fortunately, solar energy, although the entire world runs on it, is rather diffuse, which is a good thing because otherwise we would all cook. It's still a lot of power. It's 1,361 watts on average per square meter of sunlight in space at the Earth's average distance from the sun. But in order to generate the power that's necessary to run smelters and cities and factories and AI data centers, you need thousands of megawatts. So gigawatts, millions of kilowatts. And that means you have to harvest the sunlight in space over literally

millions of square meters and then deliver it to the ground in a way that is, is both safe, precise, and cost-effective. So there are lots of challenges and lots of steps in trying to make that a reality. How big would the space-based solar installations need to be, to generate enough power to actually make this worth the effort? So in principle, the interception of the sunlight needs to be done by collectors, on the order, do a quick calculation, on the order of 10 square kilometers. And so the, maybe a little less, maybe a little more, but it's on the order of 10 square kilometers.

The specific concepts differ. There's lots of different ways to do this, just like there's lots of different ways to do any major energy technology, like nuclear power plants or nuclear fusion. But the platform would need to be kilometers in scale for the microwave transmitting, mission case, the transmitters tend to be on the order of a kilometer across, a kilometer in diameter as well. So these would be enormous. People have said larger than, you know, the biggest buildings down here on Earth. How do you get them into outer space? So the simplest solution to doing very large systems in space and the only real solution is to make the systems modular to package up the pieces and then to launch them into space and assemble them there.

That's the scenario for space solar power that's been looked at. There are also visions that in the long term, you might be able to do things like use in-space resources, like from the moon, and make solar power satellites out of those. But you still have to basically deconstruct the platform into lots and lots of small pieces, make those pieces, transport them, and then put them together where you want them. And then you need to beam the electricity down. Is it safe to beam something like that down to Earth? Yeah. So it's another aspect of the problem, which is very critical. And the scenarios that are being looked at most are those that involve relatively low-intensity microwave energy for that

purpose. And by relatively low intensity, I mean on the order of a 100 watts per square meter on average, which is about 10% of summer sunlight on average. The peak would be a little higher, like 250 watts per square meter, but still a fraction of the intensity of sunlight. And the energy is being transmitted at microwave frequencies, which are long wavelength. They can't cause cancer, the way that ultraviolet radiation can cause cancer. And so you still have to have proper precautions. But in terms of the health and safety of flora and fauna and people, there should not be an issue as long as you take those precautions. The deal that the company we mentioned, overview energy, signed with meta to build a solar farm, would apparently

produce something like a gigawatt of energy, which is enough to power around. around 800,000 homes. Does that seem in the realm of possibility in the technology that we have now? It certainly is, there's no new science that's required. It's not at all like some other future technology research topics. There's no new research that's required. There's a lot of engineering that's required. And it's got to be scaled. I would say, you know, 10 years ago, having 10,000 satellites in Earth orbit providing Internet services across the planet was unthinkable, and yet SpaceX was able to do it in a handful of years because there was no research, no new research, but there was a lot of engineering and a lot of investment needed to be made. I think the same is true to realize within a

finite amount of time, i.e., I'll say either a handful of years or a double handful of years, six to twin years to get to the point of being able to deliver large amounts of power from space. One of the reasons why people might be skeptical is because, as you may well know, tech companies make eye-catching announcements about energy deals to fuel the AI revolution. They speak in language that is extraordinary and with wild promises. People call it Braggawatts, that they're just joking. That's what they're kind of speculating about is that, you know, I have more Bragawats than you.

do. Is there the possibility that this is just marketing hype, that that meta is, is selling its own game here? I think that the answer is probably no, that it's got a certain element of public relations to it. I would say that it may be more that they're trying to show that they're really leaving no stone unturned and that when they install their data center in your town and they come looking for your megawatts, it's not because they haven't looked everywhere to try to solve the problem elsewhere. Also, I think it's kind of long-term thinking. In the longer term, there have to be new solutions because the amount of power that's going to be needed for AI data centers terrestrially in the coming several decades is on the order

of a thousand gigawatts. It's a terawatt of power 24-7. And that's just five years ago was not on anybody's horizon. So it's certainly a clear, there's a clear market demand. And space solar power is certainly a prospective solution, even if it's not one that's on the shelf at the moment. Let me ask you just about a couple of other concerns that people have raised. One is just the cost of this.

There was a report from NASA that suggested that building solar infrastructure in space could be as much as what, 80 times more expensive than building renewable energy here on Earth? Are they wrong about that? I think that that conclusion, and I understand you're going to have a guest in a few moments who was involved in that study, I think that that number reflects the assumptions that went into it, and in particular assumptions about the major cost drivers of large, ambitious systems in space, such as low-cost launch, and that if we are successful, if the world is successful in achieving much lower-cost launch,

the deployment of large mass-produced space systems, in-space robotics, if all these things happen, then space solar power will be drastically cheaper. If those things don't happen, then it won't. So there is a success path, and it involves advances in several technologies. but it's not an unthinkable path, given the progress that's been made in other areas in the last decade.

Do we need more things floating around in the low Earth orbit? We have all sorts of space debris that's out there right now, and people are trying to figure out what to do with it. Yeah, this is a big point of discussion within the community. There are several companies and players that would like to put lots of new systems in low-earth orbit. I happen to believe, and I'm a proponent of putting everything in a high-end, Earth orbit, such as a geostationary Earth orbit or geosynchronous Earth orbit, and all of the economic numbers that I've looked at the last couple of years have assumed, if you take it out,

you've got to bring it back. You know, you clean up your campsite. It can't afford to have huge amounts of additional debris. And so it's certainly an important part of the overall economics and technical planning to look to reusable systems and to not throwing things away as you're done with them. Just finally, what is the opportunity here, do you think, beyond AI data centers? I had read that, you know, you could provide something like 80% of Europe's energy needs by 2050 through this, that each satellite might generate the equivalent of a nuclear power plant.

From your perspective, what is the opportunity here? For most regions, the opportunity is to supplement and to offset the need for fossil fuels and for long-term battery storage. For a few markets, if they want to move to solar power and away from fossil fuels, and Canada is certainly one of these, terrestrial solar is just never going to be a significant player. Terrestrial wind, yes, but rooftop solar is always an attractive option, but lots of times the sun doesn't shine. Having a power plan in space gives you the opportunity to deliver power to markets like Northern Europe, like Northern Asia, that would otherwise not be addressable by solar energy in any meaningful economic sense. and that's what space solar power really does. It's not the answer. It's not something that's going to replace all these other options.

It's something that can enable a much broader market opportunity for terrestrial renewable energy. John, good to speak with you about this. Thank you very much. It's a pleasure. John C. Mankins is a former NASA physicist, an expert on space solar power. He was in Santa Maria, California. You know that feeling when you reach the end. of a really good true crime series.

You want to know more, more about the people involved, where the case is now, and what it's like behind the scenes. I get that. I'm Kathleen Goldhar and on my podcast, Crime Story, I speak with the leading storytellers of true crime to dig deeper into the cases we all just can't stop thinking about. Find crime story wherever you get your podcasts. Not everyone is as hopeful about the prospects of building solar infrastructure in space. Charity Whedon is former head of technology policy and strategy at NASA.

She's also a Royal Canadian Air Force veteran who spent time at the Canadian Embassy in Washington, and we reached her in Washington, D.C. Charity, good morning to you. Hi, good morning. What do you make of the promise that John is talking about there? We'll get through some of the more specifics in a moment. But big picture, is this as promising of a technology as some people will believe? Well, with such a heady question like that, you know, I've done a little of everything in my career.

learn to ask questions in different angles. And the biggest question is to ask, what's the problem we're trying to solve, right? Are we trying to solve energy demands? We're in an intelligence age, not just a data age, you know, reductions in production of fossil fuels, all the general economic uncertainty. This all adds up to what is this project going to help solve. And so that's really a good question for meta. but on the large scale of this, space-based solar power,

is one of several potential solutions to the problem of an energy demand society. So the deal that Meta signed, and presumably what Meta is trying to solve, is this insatiable need for power to fuel these data centers that will, you know, goose its artificial intelligence network. this proposes building a solar plant in space that would generate a gigawatt of power. From your perspective, how big would something like that be? Well, it would help power one kind of large data center, but you heard from a previous color that it's about a 1,000 gigawit differential between the here and where we need to be

if we're going to leverage all this artificial intelligence. So in my perspective, this is a drop in the bucket, but an important drop. that we need to analyze along with other potential power sources. What about the cost of something like this? Again, John C. Macon suggested that perhaps NASA is overestimating how much it would cost to build solar in space, that if a number of things were to fall into place, perhaps it would be a lot cheaper than the suggestion that it might be 80 times more expensive than building renewable energy here on Earth. Do you think that is it possible that you're being too pessimistic about that?

Well, in the report, they look at a data-driven method to look at this question. And I look at these big problems in three ways. What are the technology chokepoints? What are the economic checkpoints and the policy checkpoints? So if we're sitting on the economic checkpoints, sure, cost of launch is one of them. But supply chain and the availability of items that would go into building such a large-scale project is also something to look at. Also, the maturity of the market. And so I think this is just a data issue and a math question.

Just like Mr. Manchin said, you know, it depends what the data you put into a model of figuring out what the economic value of this all is at the end of the day. So you asked what is the problem that we're trying to solve? What do you think the problem that those who are in favor of this, whether it's, you know, the Japanese government, whether it's these individual companies, what is the problem that they see in front of them? I think there's going to be several answers to this. But one that I'm hearing a lot from industry specifically is there's no regulation in space. We don't have to worry about that like we have to on Earth where you have to look at the environmental issues and rising energy costs of your neighbors and the neighborhood. That's not so true to just say there's no regulation in space.

there's a lot of regulation in space, and it just means that the risk is transferred into the orbit instead of on Earth here. You were talking about the debris potential, and also there's ethical and societal risk, right? If there's a large scale number of these, then there's the question of the night sky and astronomy as well. So not to not answer your question, but I think there's a lot of reasons industries interested in this, and one of them could be the regulatory path that they feel is easier. Do you tie that to the general interest in space more broadly right now? It seems like there's a lot of excitement,

not just about this idea of harvesting the power of the sun, but about being back in the space race, if I can put it that way. Oh, absolutely. Like, we are finally back into it, heading back to the moon. We saw that with Artemis II and Jeremy Hansen. And I think that has energized, both industry and the public, and for industry like AI, space, quantum, all these advanced technologies are really accelerating, right? Everything is accelerating the technologies, the use of them.

And so we are looking for new pathways to fit that insatiable appetite. And space is the logical place because, hey, space is big. And it is big. But we put things in specific orbits for specific reasons. And so those orbits can get congested. One other thing to think of here is space-based solar power can be really useful on the moon, right? If we are going back to the moon, we're going to have activity on the moon. You're going to need power sources.

That is a huge problem right now to deal with because of, you know, the darkness and the cold and all that. So there could be practical uses for civil space agencies or industry to use space-based solar power on the moon as well. We have big problems here on Earth, climate crisis, top of mind. But there's an energy crunch. We're saying that right now, given what's going on in the Middle East and concerns around where a reliable supply of energy might come from. Even if this is expensive, even if there are concerns, do you think it's worth trying? I think it's worth exploring.

If you can look through the technical, economic, and policy choke points, and then you've got to ask yourself, what could go wrong, and then weigh that against the project. So security-wise, safety-wise, sustainability-wise, and societally. And so I think it's worth it to evaluate it for sure and evaluate it against other options. At the same time, like I said, the world is accelerating and we need to make decisions as well. So what do we need to make decision today that will be a benefit in 20 years? These are long-term projects. Will this be as effective in 20 years when it actually gets built than it is today?

I know we have an energy crunch today. So what can we build as a suite of power systems that'll bring us into the future? So what would those other options be? Miniaturized nuclear fission. And there could be other green tech. I think there needs to be an all of above kind of evaluation of all these options and their purposes. And so in the all of the above, I mean the yes and, not yes, but kind of approach. Right.

Is something like this part of the all of the above? I think so. again, evaluated. Find out what are the actual economics and the marketing requirements here. Find out what other policy issues we need to fix. The exciting thing about actually saying yes to something like this would be you're going to have to fix a whole bunch of things in order to get this to be successful. So you're going to need to create an on-arboard servicing environment to build these large structures. You're going to need to have proper space traffic coordination and management in orbit in order to, mitigate the debris issue. Putting a new type of satellite system in orbit requires a lot of background regulatory discussion. And so you're going to have to work your way through these. These are not hurdles per se. They could be opportunities to fix and get us into a position where we can actually leverage our orbits. Just two final things. One is do you worry, and you've hinted at this around the issue of regulation, do you worry that the tail wags the dog and something?

ways, that these mega companies like meta need this kind of power and that they may dictate how something like this moves forward. True. I mean, a single gigawatt power source for them would be usable, but what are the cost to other players, either in orbit or on the ground? You have to think of that. So maybe, and again, I go back to my original item that I said is like, what is the problem we're trying to solve?

And so if it is truly, we don't have enough energy to have our company grow so that we can manage AI systems, then this is a valid thing to look at. And as you said before, if that's not the problem they're trying to solve, then maybe there's other ways to do that. Just finally, skepticism and critical thinking is really important here. But is there something valuable about dreaming big like this? even if you think that this is some sort of far out idea, and I can imagine there are a lot of people who are listening who would say that,

that may not come to pass. Is there something valuable about having that kind of huge big dream, with the idea of something almost outrageous being seen as something that might be possible? Yeah, I like to tease people that I'm like a human space elevator. My feet are firmly planted on the ground, but my head is always in space. Think about it. We have been an earthbound. society. We've now commanded the orbits out to geostationary orbit. That's great. We've gone around

to the moon and back, but we haven't really grasped what it means for society and humanity to leverage another planetary body. And now space-based solar power could be part of how do we leverage the Earth-moon sun system in the scale of things that are happening right now. This could get us out into the solar system a lot faster. So I'm just as much as a dreamer as everyone else, but my feet are firmly planted on the here now as well. And how do we get from here now to where we want to go? That's really well put. Charity, really good to speak with you about this. Thank you very much. Thank you. Charity Whedon is former head of technology, policy, and strategy at NASA, and a veteran of the Canadian Armed Forces. She was in Washington, D.C. You've been listening to the

current podcast. My name is Matt Galloway. Thanks for listening. I'll talk to you soon. For more CBC, Podcasts, go to cBC.ca.ca slash podcasts.