Is space-based solar power realistic?

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Speaker 1: Hey, Kelly, do you guys have solar power over there at the science farm? We do. We actually pretty recently installed solar panels on top of one of our barns. And so does it give you like all the energy you could ever want? No, not all the energy we could ever want. I married a man who would like to build a giant laser, and so he's always going to be disappointed. But it gives us some power. Well, does it give you all the energy you need? I mean not quite. It's cloudy where we live, and then there's nighttime and the batteries aren't quite up to the task. Who needs energy at nighttime? Jeez? Or like in the winter, you guys are way too demanding. Yeah, we could just put on like five layers of socks. That might get hard for Zac to wear socks and sandals, but I'm sure he'd persevere. Hi. I'm Daniel. I'm a particle physicist, and I'm the co host of our podcast, Daniel and Jorge Explain the Universe. And I'm Kelly Weener Smith. I'm an adjunct professor with Rice University and I study parasites. And welcome to the podcast, in which we talk about everything out there in the universe, the tiny little particles that wiggle around beneath your toes and in your toes, and the huge mysteries of the universe, how it began, how it will end, how it all works. We talked about all that crazy stuff and try to break it down and explain it to you. My normal co host, Jorge cham the creator PhD Comics, isn't here today, but we're very lucky to have our returning regular guest host, Kelly Wiener Smith. Kelly, thanks for joining us again. Yeah, my pleasure. I'm excited to be back. It's a lot of fun. Well, we try to have fun, and we also try to talk about the science. And we talked about the mysteries of the universe. We talked about the tiny little particles, but we also like to talk about how things work and whether things will work. We'd like to explore technologies. We've talked to this podcast about how l e Ed's work. We've talked about how solar panels work, and we've talked about things like space elevators. And I understand Kelly, that you're becoming something of an expert in how space technology and space colonization works. Yeah, our upcoming book is sort of on that topic. So we've been spending a lot of time reading about these sorts of things, and soon has had a chapter on space elevators. And are you excited to think about this kind of stuff because you think like everything in the future will be based in space, of space farms and space schools and space grocery stores. Well, I have the sense that we are maybe a little bit too overly optimistic about how great it's going to be to live in space. But I do think that at some point we'll have space settlements and we'll have lots of cool stuff going on in space. And how we're going to power all of that and and make this awful environment habitable is a very interesting question, I think, because it is kind of an awful environment. I think it's amazing that spaces is sort of like cool sheen to it, right, and it is some out there, it's like part of the universe, But it's also kind of awful, right. I mean, it's like not a cozy place to be, no. I mean, I think you look at a picture of the Moon are Mars, and you can sort of imagine places on Earth that looks sort of similar and sort of convince yourself like, oh, it's not that different, but no, it's super different, and it's super unpleasant and it's definitely trying to kill you all the time. And that really makes us cherish life down here on Earth. You know, we are really lucky to get to live in this warm, atmospheric little slice of the universe that's wet but not too wet and has all the right conditions for our kind of life and our cozy lifestyle. And so I think another way to look at space is like as a resource, a way to support and improve life here on Earth, rather than as an alternate for life on Earth. And I think there's a lot of enthusiasm about that. But I also think there's a lot of reasons why getting things from space to Earth is really difficult, and those are maybe some of the big things we need to overcome so that we can make space improve our lives down here. Right, We need like a better highway between here and space so we can take better advantage of all of its resources, yes, exactly. And also we have to be careful about Earth being a gravity well, so you don't bring, for example, an asteroid with great resources too close and then have a sort of dinosaur event happen again. So it's a little sensitive talk about cell phones. Right, Oops? Ye, right, whoops, extinction level event. My bad. Well, one of the big issues of course facing us down here on Earth is energy and how to get clean sources of renewable energy that are cheap and that are easy to distribute, and that are consistent, and that can heat your toes on a cold winter night, even on the science farm. So what are some proposals. Well, obviously there's been a big surge down here on Earth of solar panels and green energies such as wind, etcetera. So that's been helping a little bit. But I get a little worried when I look at these projections from the I p c C about like the various paths we're going on if we only use like twenty or thirty or fifty renewable energies for the next few years, like the nerves for increasing global surface warming temperatures still look pretty dire. Yeah, and I'm not super optimistic that we'll be able to switch to more climate friendly technologies like nuclear because they have sort of other big downsides when you've got humans using it. Absolutely and so people have been talking about crazy new proposals to supercharge our solar power industry, to make it much more efficient, much more dramatic, much more available by connecting it to space. Yeah, so what would that look like? How the heck do you do that? And that's the topic of today's podcast. Today on the program, we're asking the question is space based solar power realistic? Because you know, we can talk about space based whatever, and you can spend ten billion dollars doing some proof of principle or a hundred billion dollars, But if we're going to talk about something like delivering power to people down here on Earth, it's got to be economical, right, It's got to be robust, it's got to be actually realistic. We've got to be developing an industry people actually want to invest in and work in, not just some fancy thing for a nationalistic pride. Totally and so okay, So we've got solar panels on Earth, and the price of solar panels is plumbing quickly. So, like Zach and I've been together for something like fourteen years now, and almost every year in our relationship we've checked the price of solar panels just because we're both excited about renewable energy, and last year we were like, we can afford it now, And partly that was because of tax credits and stuff, but also it's because the price of these panels is going down a lot. And so when you can put these cheap panels on your house, is why would you bother putting them in space? Right? So let's dig into that in a moment, But first I want to ask you, like, what made you pull the trigger? Was it really like it's below the threshold where we can afford it. We keep looking at this and keep thinking, you know what, next year they'll be cheaper. If we just wait another year, they'll be cheaper. So at what point do you decide, well, they're cheap enough and now is the time to buy them. So I think the trigger for us was that there was a tax break for something like thirty percent where the cost of the solar panels you could apply to your taxes, and that was set to expire, and so we decided we needed to do it right away. And actually a bunch of the local solar companies were just way overburdened because a bunch of people must have made that same calculation just a couple of months before the taxes were about to expire, and so for us, it was the tax break that made us decide we weren't going to wait for the price to go down anymore because we thought it would be a while. And also we had finally purchased our own house, and this is something we had been, you know, dreaming about for a long time, so we decided it was time to go for it. And it's really interesting to see the evolution of this. Twenty or ten years ago, solar panels were really pretty expensive, they were hard to make, they didn't last very long. We weren't that good, but you know, people were buying them, and the industry got started and the government gave it some pushes, and now we have this very vibrant solar panel industry where the prices are falling rapidly and lots of people are buying them, and so it's sort of builds on itself. It's sort of like consumer electronics, you know, once it gets going and the big marketplace comes in with all of his cap at all, than things that just get cheaper and cheaper and easier and easier and better and better. But one thing that is not getting cheaper and cheaper as fast as I think we would like is the batteries that go with the solar panels. So we live out in the middle of nowhere, and we sometimes will lose power for like a week. The previous owner at least told us that, and so we asked the solar panel company, like, so we should buy batteries, right, and we'll store up a week of power and when our power goes out in the middle of winter, we'll live off of the batteries. And the guy was like, no, no, no, you should still buy a propane power generator because the batteries are way too expensive. We're not there yet. That's totally not worth it. And so I feel like solar isn't going to be a really great solution until you can actually be storing the power from the sun even when you don't need it. And the things like Tesla are helping to drive down the cost of these batteries because they're you know, making them more efficient and better to put in electric cars. But I think it's still in a lot of cases, the technology is still not there yet at a reasonable price point. And I think you put your finger on what motivates space based solar power, which is that you can't get solar power on Earth twenty four hours a day, three sixty five days a year because it's nighttime sometimes and you know it's cloudy sometimes, and so what if you could like beam that power from space anytime, any day, no matter how cold it is and how overcast it is. But we'll get into that in a moment. First, we surveyed our listeners to hear what they thought about the prospects of having solar power come down from space. So thank you to everybody who volunteered to answer random questions on the internet. If you're excited to participate and hear your voice speculating baselessly in the future, please write to us two questions at Daniel and Jorge dot com. So here's what people had to say. I think, yes, maybe not for us on the ground, to to the limits of currently available extension codes, but definitely important for everyone who is or regis stationed in space. I think it is uh something is I'm assuming that would be either a dison sphere or a the what you call it solar solar sale. I think very large scale is impossible. I don't think we have enough matter in the Solar system to make a dicen sphere. Um, but I think some things can be made of it. I guess the problem would be getting the power from space down to Earth. Again. Um, I guess it would be a good idea to have solar panels outside of the Ear's atmosphere because you probably get more power because there's no clouds and things. But then you'd have to get the power down to the surface. So I don't know if you can beam power? Is that too star Trek I don't know. Um. Otherwise you could do it with batteries, I guess, and then transport it, but that would be very expensive. Space based solar power is not realistic now because I don't think we know how to get the power back to the Earth. If we're going to use it on the Earth, I feel like that would be a very hard engineering problem. Like we we already have trouble sending solar power distances here on Earth. So if it's collected in space, that seems logistically like impossible. Well, it depends how the technology will evolve, but for now, no, But who knows how what we will do in the future why not? So what do you think of their answers, Kelly, I thought those were super interesting answers, and I thought they brought up some important points, like how do you get the power back to Earth? So they were well thought out answers. What about you. I heard a lot of skepticism there, which I think is well motivated. There's at least one person who misunderstood the question. I think I was talking about like solar sales and whether you could sail on photons from stars while you're sort of far away from a solar system, which is another totally fascinating question and would require like massive lasers to push on those solar sales. But I think the question of like building solar power in space and beaming it down to Earth does seem pretty complicated and problematic. But you know, maybe we're is that the early stages of this industry, back when solar panels on your roof were expensive and flaky and hard to arrange. Maybe we're just sort of in the early days and we need to sort of get the ball rolling. Anyway, we'll dig into it. So you mentioned in the IBCC reports that it just didn't seem like renewables were maybe going to be enough to deal with the climate change problem, like what is holding us back? Why can't we just use renewables for all of our energy and you know, stop using things like coal. Yeah, well, I think you put your finger on it earlier, which is that you don't get sunlight all the time. And in some cases there are places where you get like a lot of sunlight exactly when you need it. For example, if you live in Arizona and you need energy in order to cool your house, then you're getting a lot of sunlight right when you need to cool the house. Sins to the energy production produced by the solar panels are very close to the energy needs where you need it to drive that air conditioning. But that's not always the case. If, for example, you're living in the dark, cold northern Scandinavian winter, then you're not getting a lot of solar power and you need power in the winter to stay warm. And so the bottle neck there is, as you said earlier, storage and transportation, Like you could have a huge solar farm somewhere in the Sahara or in the Mojave Desert that produces enough powerful whole country, but getting it from there to somewhere else and storing it is very, very expensive. Battery technology and transmission losses make it essentially totally uneconomical. Okay, so solar panels are just never going to take care of some parts of Earth, that's right, because they can't get energy twenty four hours a day and they can't get energy three sixty five days a year. And a similar problem for wind. Right wind also directly produces electricity, and electricity is hard to store efficiently and hard to transfer efficiently. Is this the kind of thing where if we improved our grid dramatically things could improve a lot? Or are we limited by the physics of transmission loss as you go, even with a great grid, we still couldn't get the power to place as we need it. Transmission losses are pretty tough, and we're talking about you know, across the country or across the world when we're talking about storage, and storage is pretty expensive. So you know, you can't rule out future breakthroughs in battery technology. And actually, we're gonna do an episode in a few weeks about electric airplanes, which require innovation in batteries to make them lighter and more powerful, but current ideas don't have us getting there, and so we have this limitation of just sort of producing the power at the right time and in the right place where it needs to be used. All right, So solar power is great, but you've got these problems with trying to get it from place to place and problems with not having enough of it in some of the places that you need it. How does spending the incredible cost of putting solar power in space help us overcome these problems. Well, the basic idea is that it's always sunny in space, So you can have these solar panels up in space and they're always seeing the sun. Right, they're gonna be a high enough orbit that they're not gonna be in the Earth's shadow for very long at all, like a very tiny fraction of their time. And of course they're above the clouds, and so they have basically continuous generation of power. And you know a lot of energy is lost when the sunlight passes through the atmosphere. It's like reflection and absorption and that kind of stuff. So the idea is that you start out collecting much more solar power five six, seven, eight times as much as the equivalent ground based array, and so that provides you the ability to gather more power and also to gather power all the time. And because you're in space, you can reach anyone who might need that power anywhere? Is that the idea? So like you can get those people who are living in Norway in the winter. Yeah. So that's the other issue is like you generate this power in space, then what do you do with it? Right, Because we have already solar panels in space, like every satellite that's out there, and the I s S has solar panels. It's a very well established way to generate power in space for use in space. But you want to generate power in space and then use it to build you know, Zack's big laser or whatever, then you need to get it down to Earth. Right. So you might be imagining like big wires draped from satellites down to Earth. Obviously that's not gonna work, right, huge problems there, and so the idea is to beam it down to Earth. So you collect the power in space and then you transform it into microwaves or lasers and beam that down to Earth to some receiver which then picks it up. And we have a fair amount of experience with working with solar powers and space, right, So you mentioned the I S. S has solar panels, solute Skylab mirror. They probably all I'm fairly certain they all had solar panels. Also, the rovers on Mars have solar panels yep, yep, yep. And so we have some information about how solar panels persist in a vacuum and how long they survive and how well they do as they move in and out of the sunlight. So which would mean they're dealing with these massive temperature changes as you go in the area where you get hit with the sun versus when you go in the shadow of the Earth. And so I guess we have a fair bit of information about the use of solar panels in space. Do you think that's fair to say? Yeah, I think we definitely have some experience. I don't know what the history of repair is for those missions, if they're like constantly repairing and replenishing the solar panels on the I. S. S. Because of micromedia, it's a radiation damage. So how long have people been thinking about this idea? Is this like a brand new idea or an idea that's sort of been floating around for a while. I was doing a little bit of reading, and it turns out this is an idea that's been bubbling up for decades. Actually, there was a first paper about it by a Russian scientist who the name I camp pronounce can pronounce that name, Konstantine Solkovski. There you go in the nineteen twenties and sort of speculative idea, and then I think it's sort of burst into public imagination because of a short story by Isaac Asimov. He had this device where he would collect solar power and then beam it to various planets, like around the Solar System, but you know, that's science fiction. And then it trickled back into academia. In the late sixties there was a paper by Peter Glazer sort of like trying to take this topic seriously and break it down and ask the questions about what would work and how much it would cost. So it's been bubbling around for you know, several decades, and now people are really starting to work on it, developing the technologies, thinking about how to beam it down to Earth, how to make it economical. The advent of cheap launches from companies like SpaceX or bringing like you know, into the realm of the possible. All right, So let's take a moment to talk more about the fine details of what exactly would need to happen in order to make this technology work after we take a quick break. Okay, So it's a little hard for me to imagine all of the details about what will the solar panels look like, how much energy will they be creating, do they need to be repaired? How do you get the power down to Earth? So can you give us some more details about how this is all going to come together. So there's a lot of different ideas for how to make this work, lots of different sort of conceptions. Some of them have, for example, huge mirrors that focus light onto a few solar cells and gathered together, so you're like capturing sunlight from a large area and then focusing onto just a few solar cells. Other ideas are just have like massive sheets of solar cells just like you know, lots and lots and lots of them to capture the energy. So there's a lot of different sort of strategies for how to build this thing and how to make it work. And we'll talk maybe in a little bit about which ones are more economical and which ones are more feasible, But one of the biggest questions to have to deal with is how to get this power down to Earth? Right? And it seems a little weird, like you collect the power up in space and then you need to beam it down to Earth. It's a little counterintuitive because it was already sort of getting beamed down to Earth, Like the Sun is already beaming it's power to Earth, right, So like why do you need to capture it and then like beaming down to Earth. I was thinking initially, maybe it's more energetic, maybe they're like focusing, so the beam of power from the space array of solar panels is like more intense than sunlight. But that's not actually the case, and that would actually be quite dangerous because that's basically building like a huge space weapon and shooting it at the Earth. And so there's this limitation where you basically can't beam down energy at higher intensity than natural sunlight. So when I hear that, my first thought is, well, then obviously it's not worth it. So what am I not understanding? No, that's a very reasonable reaction, because you have to like build this space array to capture the energy and then beaming down to Earth and then you still need to build on array on Earth that's you know, about the same size, because if you want to capture this energy on Earth, you need to build something that's going to grab it. And for example, if you're using microwaves, microwaves have a really long wavelength, and so you might need for example, like a rays on Earth that are one to three kilometers wide just to capture this energy. And if that energy doesn't have more intensity than sunlight, you might as well just have built a ground based solar panel right there. Right, why capture in terms of microwaves from space instead of just like a natural sunlight falling on the Earth. And the answer is that the source of light from space should be more constant, right Like, if you're on Earth and you're just lying on sunlight, then you're not going to be getting it at nighttime, and you're not gonna be getting when it's cloudy. And people who don't live in southern California like I do, know that they don't get more than a few hours of like really equivalent solid sunlight on an average day. So the difference is that it should be constant, that you should be always getting this microwave power beamed down twenty four hours a day, sixty five days a year. So the power we get sent to some giant station that collects it, and then it would be sent through the grid to our houses. And you could have several stations scattered all around, and the solar panels in space could direct the energy where it's needed, so it's not like linked up necessarily for all time. Between one set of solar panels in space and a receiving station on Earth, you could decide, oh, Australia needs more power, or oh we need more power in Scandinavia, and you could redirect this power as needed. Because you're just pointing it from space. It's like you're shooting it from space down to the receiver on Earth and that would be sent as microwaves. So there are two sort of technologies people are considering. One is marcro waves and the other is lasers. Micro Waves, you know, are just photons. There's just another kind of light, but it's light with a very specific wavelength. It's the same kind of radiation, same kind of light that exists in your microwave oven to heat up your food. So you know, if you beam microwaves at something, you will heat it up. They contain power, and the microwave is just tell you, like roughly what the wavelength is of the light. And so we're talking about centimeter length wavelengths, which is not actually that small, you know, compared to like visible light, but it's micro compared to you know, like much longer wavelengths radio light. And so these are great because they can pass through clouds. For example, so you shoot a microwave, it's basically clouds are invisible to it. The clouds are totally transparent, and so that's pretty nice. And these things could be like up really far away in sort of middle Earth orbit or geosynchronous orbit, like thirty five kilometers above the Earth, and they could beam the light down in terms of microwaves, and then on the Earth surface you just need some sort of like microwave antenna which is just like a big chain link fence essentially to capture these microwaves. So this might be a silly question, and but so I wouldn't want to be in my microwave. That would be a bad place to be. Do you have to worry about, like if a plane passes underneath the microwaves that are getting sent down to the power stations on Earth. Would that be a problem or or not. It's not a sarily question at all. I don't want to be in a microwave either, especially a space based microwave. They could like track me and shoot me wherever I go. The idea is to limit the intensity to the intensity of normal sunlight, so you don't get any problems like that because you don't just have to worry about airplanes. What about like birds. You don't want to create like a death zone where you have like a column of birds that are like constantly dying and falling onto your microwave array because you're killing them more insects or anything else, right, you don't want to be changing the weather. So that's why they limited to the roughly the intensity of natural life. But that is definitely an experiment. When we talked once on this program about five G, which operates in the same sort of wavelengths, we don't have sort of knowledge about what it's like to live under low intensity constant sources of micro way of radiation because people haven't done it before. So we might discover some bad news, some bad consequences of this if you live near the station. But current understanding of physics and biology, is that that wouldn't be dangerous to humans, Okay? And then different questions. So you had mentioned that the solar panels would be in geosynchronous orbit, and geosynchronous orbit is like really high up. So the International Space Station is in low Earth orbit. Geosynchronous orbit, as I understand it is really high up, and that's where you need it to make sure that an object stays over the same spot in Earth all the time. And so if you are super far away, like farther than where a lot of those satellites, you know starlink for example, is do you lose power on the way and is that a problem or do microwaves not sort of dissipate over distance. You definitely lose power and that's definitely a problem, and when we talk about the economics of it, that's definitely an issue. You can't transmit energy efficiently basically, ever, and if you're beaming power over long distances, you're also going to lose some power. They're hoping for efficiencies of like fifty to eighty percent. They actually have done some tests they beamed power using microwaves. This is the test they did in Hawaii and went for a hundred miles and they're able to get reasonable efficiency, but it's definitely an issue at every stage you're gonna be losing some energy. You know, converting the sunlight into electricity is like maybe thirty efficient if you think very optimistically, and then transforming that into microwaves is not gonna be hundredsent efficient. And then the transmission down to Earth that's not going to be hundredsent efficient, and then the conversion from microwaves back to electricity is not going to be a hundred percent efficient. And so you multiply all these numbers together and starts to get smaller and smaller. So this whole question of whether it's feasible relies on balancing this like a multiplier factor of your getting more power consistently with the expense factor of you've got more steps in the chain where you're gonna lose efficiency. And also it's pretty expensive chain to build. I mean, this thing is going to be in space. That all sounds super complicated. So you had mentioned they could do microwaves or lasers. Do lasers make any of those equations play a little bit more nicely? So microwaves and lasers the two ideas lasers are a different idea, and the goal here is to make smaller devices because lasers can be more focused and they can be narrower beams just because the frequency of the light is higher and so it doesn't like disperse as much as it comes down to Earth. And so for example, you can have like a two meter wide beam instead of a one kilometer wide beam, so you can have like smaller stations where you're capturing this energy. You don't need to have like a massive area on the Earth. It's like a more intense, narrow focused beam. And the idea there is that also the lasers could be closer, like they don't need to be as far away, so you can have like a larger number of smaller satellites beaming the energy down with lasers instead of microwaves. But of course, you know there's some dangers. They're like you're talking about more intensity in your beam. You talk about literally shooting lasers at the Earth from space. That gives me the Heabie gps, so it gives me the hebe gep is too. But like microwaves, is it the case that you would just have to make sure that you never are generating more power than the sun, Like, are these just gonna be super weak lasers? Yeah, exactly, you need to not be creating death rays from space, so they would have to be pretty weak lasers, and that limits the power there, right, So I think these days microwaves are sort of on the ascendants when it comes to space based solar power because you have this limit on the intensity, which means that in order to get enough power, you would still need a very large receiving array, so you just need lots of lasers, and so it might be that you would need like a huge number of these lasers. The other problem with lasers is that clouds aren't as transparent to lasers as they are too microwaves. Microwaves can mostly pass through the atmosphere in the clouds without losing energy, but not true for lasers, Like clouds can block lasers much more efficiently than they can block microwave beams. That sounds like a pretty big problem problem exactly. So I wonder if there's a geopolitical problem here too, So you know, when you create this system, you make sure that you're not blasting the Earth with lasers that are super powerful. But like, for example, would we feel comfortable with North Korea saying we have a power problem and we want to use space based solar power, you know, to generate power. So is this the kind of thing where you might be able to say the international community is okay with, for example, the United States having this power because we think they'll follow our rules, but we won't let North Korea anyway there. Do you think there's geopolitical issues that might come to play here? Oh, I'm sure there are, and I'm not up to speed on like what the treaties are about how we use space and what the rules are up there who's allowed to launch these things? I think it's essentially there are no rules, right. We certainly haven't been able to like limit North Korea from launching satellites or missiles or anything like that. So as we move into an era where space is a international resource and one where they're competing interests, will definitely have to figure all this stuff out. Maybe a model for this is, you know, how we handle international sea waters or Arctica or stuff like that. Yeah. I've been talking to some space lawyers and it seems like, if nothing else, it's a very interesting time to be a space layer. With our space lawyers Are they lawyers in space or are they lawyers about space? Or what's the deal with a space lawyer. There's a job that will always seem fake to me. It will always seem like something that belongs in a sci fi novel. But no, those are lawyers working on questions related to space, and it's a super active field, and I think they've got tons of work to do right now as space gets cheaper, and so what do they think is going to happen to, like how we handle these competing claims and interests in space. It depends on what topic you're referring to in particular. So there's a lot of debate right now on topics like our countries allowed to go to the Moon and extract their resources and use them, and the Outer Space Treaty has some sort of vague language about how you're not supposed to be able to like take stuff, and it's supposed to be for everyone. Everyone is supposed to benefit. But the US is sort of interpreting right now that we can go up there and if we extra resources, our companies can then sell them, and that's not the same as claiming sovereignty. So the big thing the Outer Space treaty says is that you can't claim sovereignty of any part of space, and so they would be saying, but we're not claiming sovereignty. We're just extracting resources and selling those resources. We're not saying we own the land where we did the extractions. So space lawyers are sort of trying to figure out what to do about those claims and how sound those claims are. And I don't know how that would relate to things like are you allowed to put space based solar power up when it has the potential to be used as a weapon, So you're not allowed to put you know, for example, weapons of mass destruction up in space. But there's this problem with dual use where there's things that you can say like, well, no, I'm just doing this for power. I'm trying to, you know, make sure my people stay warm, but it can also be used as a weapon, and so it becomes hard to categorize. And so you know, space lawyers are working on questions like that. It definitely sounds very space lawyery, like we're not claiming we own it, We're just taking stuff out of it and selling it for money. You know, I'm not claiming sovereignty over your house, but I'm taking your flat screen TV and selling it on eBay and keeping the cash. It gets very complicated, it sounds like it does. And I think that's kind of the lesson here is like everything in space is complicated, not just from a legal point of view, but from a logistical point of view. You know, one big problem I have with space based solar power is that it's really inaccessible. Like, if you build a solar power array on your roof, it's hard enough to get up there to pick something, or you gotta get a ladder and maybe break your neck getting up there. But like if we're talking about building something and putting it in space, right, like you got to repair that thing. It's a huge problem. Remember when they built the Hubble and it had an issue and you know, one of the lenses was fuzzy. They had to like send astronauts up there in the Space Shuttle to go and repair that thing. And like, if you've waited a long time to get your cable provider to come by and fix something, imagine waiting on massive lawn schedule, right, and we don't you know, the Space Shuttle was a more versatile vehicle than the things that we have now that bring us to the International Space Station and DOC and then come back down again, and so well, I don't know what it would actually take if you wanted to have a human go to repair your space based solar panel. I don't know that we have good technology available currently for that sort of delicate, like going to a very particular spot in space kind of job. And so we'll talk in the next segment about the idea of how to do these kinds of repairs and what might entail and what's going on with the economics when we talk to an expert who was really excited about the prospects of it. But before we talk about that, I want to talk a little bit more about something that you mentioned earlier, which is sort of the hostile environment. Right If you have solar panels in your backyard, obviously you know it's gonna be rain and snow and hail, all these things you have to deal with. But they have the benefit of the protection of the Earth's atmosphere. But if you're out there in space, right then you're susceptible to rocks and debris and radiation and all sorts of stuff. It's a very hostile environment. It's not a nice place to be for humans or four solar panels. Yeah, I know, the radiation is super intense and it definitely breaks things down. And then in addition to the radiation, the dramatic temperature changes are problems. So on the International Space Station you can hear the station creaking as it goes from areas where it's in the sun to areas where it's in the dark. And if you've got things that are in the shadow of the Earth, every once in a while they're expanding and contracting as they get superheated by the sun, and then they get super cold in the vacuum of space when there's no sunlight, they contract again, and that's not good for materials over long periods of time. So between the intense radiation and the dramatic temperature changes, that's a lot to ask your materials to handle. Yeah, that's like station quakes right Like, it literally is like shaking and creaking as it expands and contracts. That's amazing. And then in addition to those problems, you have micro meteorites out there which are traveling incredibly fast and could easily be poking holes into your solar panels and their space debris. Space debris is a problem that becomes harder every single year, and it becomes harder the more silly humans do silly human things. And so I think it was two thousand seven China wanted to prove that they could shoot a satellite in space, just as a way of being like, look at how precise we are in our ability to shoot at things in space. US has done that, Rush has done that, India has done that. It's not just China, but anyway, they picked a satellite that was still high enough in orbit that it generated thousands I think of pieces of debris. I wish I could remember the number that are still floating around in space. And over time, you know, we leave satellites and we don't decay them and have them go down into the atmosphere. There's just more and more stuff up there that could run into your space based solar panels. And so this is a problem that becomes harder over time. And if you have a giant array, you've got essentially a giant target to get hit by space debris. And for important things satellites, the International Space Station, they have the ability to move out of the way, but that requires you know, some fuel to be able to move when you know that something is coming your way. So these solar panels might also need to be mobile to stay out of the way. And one way or another, they're probably still getting hit with stuff because we can't track the super tiny stuff with our sensors. No, you're absolutely right, and they might not just be a target of as to brethe that might be a source of space debris. Right. If they break and stuff falls off of them, and you're talking about like replacing components, they're going to be contributing to space debris. And this problem becomes as a crescendo. Right, the more space debris you have, the more junk you create as it collides into other stuff, and then you get this cascading effect where basically all of spaces just filled with junk and becomes unusable. I think that's called the Kessler syndrome. Exactly. It's just sort of like your office, you know, you can't get any work done when your desk is just like so covered in things you need to do that you're like frozen. You're like can't use it anymore. Yeah, and that would be horrible for us in so many different ways because of all the ways our lives rely on satellites at this point. So, in the proposals that you've looked at for space based solar power, do they propose like regular repair missions or do they just plan on these not being up there for so long? What do you do about this problem? Yeah, so I asked an expert about this, and he basically just accepts that you're going to have some losses and that you're gonna go up there every year and spend a certain amount of money repairing it. And he tries to factor that into his accounting, like there's a lot of factors to keep track of. There are a lot of factors to keep track of, and those factories are probably hard to estimate now. And so you know, there's a lot of lively debate about whether these estimates for the cost of maintenance of space based solar power are reasonable or wildly optimistic. And that sounds like an exciting topic for after our break. So you mentioned that Solkowski, who was a Russian guy, was excited about space based solar power and the idea has sort of gotten people excited in the US. Are those the only countries that are excited about this or is this idea taking off in other places? It's taking off all around the world. There's a project in China called Omega that is aiming to be like operational by twenty fifty, which sounds crazy futuristic, but then also sounds crazy futuristic, so it's not should have far away. And they want to be able to supply two gigawatts of power into the Earth's grid, which is not a small amount, right to make that much solar power on Earth, you did like six million solar panels. So they have this project to like actually implement this and I sort of like be on the cutting edge of space based solar power. And is this a government funded project or is this just sort of an idea at the moment. No, it's a government funded project, and like you know, all the ideas in China, all the research in China is funded by the government. And it's a funny system the way they organize everything over there, but it's definitely government funded and it's a project. And you know, the cool thing about projects in China is that they can make plans for twenty forty years and keep them because they don't have a change in government every two four or six years where they're changing direction, like throwing up their political opponents plans and tearing them up. So one advantage of an autocracy is that you can make long read science plans and you can stick to them. So that's something cool that China can do silver lining. Exactly. They've been doing good job of keeping up with their plans for like getting humans in space and putting up their space stations. They have actually been fairly consistent in their timelines. I'm sure a U S official at NASA would be envious of China's ability to stick to their schedule. Yeah, exactly, the trains run on time. But then there are also plans involving some folks here in the in the United States to build a system that works in Australia. They see Australia as a potential good test case. And this is a project pioneered by John Minkin, who has spent a long time working at NASA and at JPL, and he's very excited about the idea of space based solar power. And I had a conversation with him about the prospects and how he sees this working and the challenges involved in building this kind of system. Yeah. So one of the things I think is interesting about his proposal is that earlier in the show, we were talking about maybe having like, you know, a giant panel or giant mirror that focuses things onto a big panel, and this proposal is for lots of tiny pieces, which I think does a better job of dealing with the fact that you're gonna get damage to them from radiation and micro meteorites. It makes it easier to switch them out. What do you think about the proposal of using lots of smaller pieces. I think it makes a lot of sense. I think he's trying to move away from the concept of like, let's spend a hundred billion dollars building one Rolls Royce, but instead, let's build up the industry to manufacture these things and get the economics of scale. And if we can produce lots and lots of these things, we can get these factories pumping them out, then we can build a large system out of small, modular components. So I'm impressed that he's actually thinking about, you know, how we can get industry connected and drive the prices down to make this thing economically feasible. So I think that sounds a lot more promising than you know, building one big, expensive one which is going to cost a lot of money and then need a lot of sort of boutique repairs. I was listening to John Mancin's interviewed on The Space Show the other night, and he was saying that he envisions at some time in the for future will have these lots of tiny panels and rather than when one gets broken, just kind of throwing it out and being done with it. You know, it's made of materials that if you had a space settlement you might like to use again, and so you would go out there and you'd sort of just like legos, take out one piece and put in another piece. But then you'd take the piece you're not using anymore and then break it down and use it for something else in your space settlement. And you know, that is a super far off idea, but I do sort of like the idea of starting to think about how we can recycle the stuff that we're using in space. I thought that was fun. I always get excited when I hear him interviewed because he's so enthusiastic, and he makes me enthusiastic. Yeah, he's very enthusiastic and I like the idea of space recycling, but you know, we haven't even figured out like aluminium recycling down here on Earth, so like, where can I recycle my aluminium can up in space? It seems like a much harder problem. But you know, I do like the forward looking nature, the imagining that this is gonna be like a whole space based ecosystem in which this concept could fit and it can support it and provide it. But as with all these things, it's a bit of a chicken and egg problem, right. You know, you could support these things and if you had all these other elements, but then you need, you know, space power to get those ments. And so somebody's got to be out there advocating for this thing, making it happen, pushing it forward so that it does build up that momentum. Anyway, I had a fun conversation with John and I asked him what he thought was the most promising architecture, how he would build this if he was going to build this thing today. Here's what John had to say. The architectural approach that I think is most promising is one that involves a very large number of identical modular system elements, probably about ten or twelve different families of these system elements. And so the Solar Power satellite, rather than looking like a huge conventional spacecraft or like the International Space Station or something, instead would very much resemble almost a living organism. So like a coral reef comprises trillions of individual coral and those of course extraordinarily tiny, but then there are all so various fish and an enemies and so on, and all of these species cooperate to make what is essentially a miniature biosphere out in the midst of the ocean. Yeah. So you can hear that, Kelly, how he's describing his like swarm of little mini pieces that build up a large space farm. I think that's probably a better design than the big space solar panel that we talked about earlier in the show. Yeah, I think that makes a lot more sense. I don't really want somebody building like a huge mirror to focus energy and that could be potentially used as a weapon. Yeah, no, I agree, We're on the same page. So did you ask John, like how long you think it would take for this technology to mature? So, I know we know a little bit about solar panels on the International Space Station, but there's probably still a lot of things that we would need to figure out to make this all work. Yeah, I did. And so I asked him if he thought this is like something in the far future that he's laying the groundwork for, or something he was going to be like alive to actually see in operation. Here's what he had to say. The time to develop a modular solar power satellite do the first demonstration is like thirty six months. The time to develop the first operating pilot plant it's like five years. The time to have the first full scale solar power satellite delivering thousands of megawatts to the ground is like eight or ten years. And it's because the pieces are the size of a three or six you cubes at There's just a lot of them, and it's not this colossus. One single thing is just legos. You're just making the moral equivalent of tinker toy pieces or lego pieces, and you're plugging them together in space. So what do you think about that, Kelly? You think this thing is actually gonna be up there in space beaming power to Australia in ten years? Well, I have a couple. It was the one I don't feel like there's enough public push for this technology yet that it's going to get enough momentum to happen in years. It would be cool if I was wrong. I also think the geopolitical stuff might need to be dealt with a little bit more carefully and that could flow this technology down to So I guess I'm not super optimistic about the ten year time point, but it would be great if I was wrong. What do you think. I think you've got to be aspirational and nobody really believes these projections. I mean, if you look at like every single space project we've ever launched, it's always had, like, you know, a target date well in the past, you know, like the James Web Space Telescope, or like look at the development of the Space Shuttle. All of these things are always like ten thirty years behind. But in order to make them happen, you have to sort of push them right. You have to say we're aiming for ten years from now, and then no, in the back of your mind it's going to slip a decade or two. If you say, you know, this is going to happen in fifty years, then it's just sort of hard to get it organized. It seems like the next generation two problems. Yes, fair enough. So I asked John about the economics of it also because I was curious, like, how do you think this is going to happen? Who's going to pay for this? How do you cut down the cost of getting They're like having to launch out there in this space to actually build these things. And so you can hear John's enthusiasm in his response, everybody's got a rocket company, but almost nobody is building new kinds of satellites because it's just not what they're investing it. We actually think that this will be like a snowball. Once this gets going, We think lots of people will want to have a play, as it's called in space solar power. But we need that catalyst. We need a catalyst to do the initial prototyping, build these modules, put them together, validate that they work the way that they have to work. There's no magic in the engineering, but people are gonna want to see it once that happens. We see these power plants as being developed and deployed through a mixture of more or less conventional private sector investment, where private entities invest maybe in a new power plant and the rest of your debt. The Golden gate Bridge was paid for by It was secured by the then newly formed Bank of America. Debt helped pay for the big Big in Boston. For the full scale systems, it'll be a mix of debt and more conventional large scale investors who want to own a share of selling two gigawatts per twenty four hours per three sixty five days a year forever. So you can hear his enthusiasm there, Kelly, He's like hoping that these costs are really going to come down, that people are going to be developing cheaper launches, and that it's gonna be so like the next Gold Rush. And I hope he's right. I worry that the cost of solar panels going down is going to make this stuff even less likely, because it will be easier and easier for more of us to put solar panels on our house. And I know that doesn't solve the problem about nighttime or clouds. But as battery technology gets better too, I wonder if we'll be less and less inclined to invest tons of money in putting this stuff in space. But again, it would be super cool if I was wrong, it would be super cool. And I think it's sort of awesome to have competing strategies here, right, Like we're pushing on space based solar power, but at the same time, you know, we are, as you say, trying to make batteries and transmission more effective down here on Earth. So who knows which technology is gonna win, but definitely humanity is gonna win. Right. If either of these things come out being cheaper and more robust and more reliable, then we're fine, right. I think it would be sort of cooler to have based based technology, but I'm a little skeptical of it. I read an analysis of John's proposal from another JPO guy, Casey Hammer, and he was, to say politely, completely skeptical. He was not believing that this thing is ever going to be a thing. And his number one problem is that he feels like John consistently makes optimistic estimates of construction and launch costs by at least an order of magnitude beyond current best industry standards. And I think that's really the key. And in a conversation I had with John, he agreed that the launch costs are probably the most expensive part of their system. You've got to go up there every year in order to repair this stuff, or even just to like send new robots up there to repair it. John estimates that would be three percent of the cost of the system. So if you have a ten billion dollar cost or your Australian system, that you're gonna be paying essentially another ten billion dollars over the next ten years to maintain this thing. And according to John, the economics workout and you're still making money and you're gonna pay off your investors, and so you can attract interest from investors because it's gonna be positive cash flow in the future. But I think that relies in really great detail on those launch costs coming down so quickly, and they are coming down pretty quickly. And I'd be interested to hear how that three percent in operation cost compares to operation costs for the upkeep of like a coal power power plant or something. Presumably it's much lower, but boy, I need to learn more about power. Yeah, it's definitely much lower. I mean, the price of coal is ridiculously low. You know, you can buy like a ton of coal for tens of dollars. You can build a coal fired power plant very very cheaply. But then you know, then you've got to keep paying for the fuel all year. And the nice thing about the fuel for your solar power plant is it's free. It just comes from the sun. But of course then you've got to get into space to repair these things. So I think what we're looking at here is sort of a race between like bringing down the cost of the launches to get up there and to maintain these things, and improving solar panels here on Earth. So, Kelly, in the end, are you more or less skeptical about the prospects for space based solar power? Well, I think the more that we talked about the physics, the more concerned I got about the equation for balancing it all out. I remain hopeful that I'm wrong, and I've actually had so in soon ish we wrote a little section about how we thought space based solar power was probably not going to pan out, and so many nice people have written me to be like, no, no, no, you have to be wrong. I love this community like it's a bunch of nice people who are trying to make the world a better place. And I'm still not totally sure about the equations, but I do hope that I'm wrong. What do you think I'm also skeptical, but I've been skeptical before, and you know, there's no limit to human ingenuity, and what it takes to it over those problems is believing that it's possible and saying, let's work hard on them. Let's figure out which part of this problem is the hardest, and let's get cracking on it. And I think that's the first step. So I'm skeptical little ever happen, but I'm hopeful that maybe it might. Well. This community has a lot of hard working believers, so if anyone can make it happen, I think these people can make it happen. So I guess we'll see. But I'm not investing in any of these projects personally, so that maybe that tells you a more personal level whether I believe it's actually gonna work. Yeah, same here. All right, Well, thanks for listening to us talk about space based solar power. You know, I think the humanity does have a future out there in space, but there's definitely a lot of horror problems to solve along the way. Amen, and thanks again to Kelly for joining us. Thanks again for the invitation. I had a blast as always. All Right, everybody out there, so stay curious, keep asking questions, and if you'd like us to talk about some other crazy futuristic technology and how the physics of it might work and whether they're gonna be building death rays to shoot into your bedroom, ease right to us two questions at Daniel and Jorge dot com. Tune in next time. Bye, thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of I Heart Radio or more podcast from my heart Radio. Visit the I Heart Radio Apple Apple Podcasts, or wherever you listen to your favorite shows. H