A book-length treatment of modern SPS designs is The Case for Space Solar Power. It has detailed cost figures but was written before SpaceX had accomplished much, estimating a cost at gigawatt scale of 15 cents/kWh. I plugged in Starship launch costs and it came to 4 cents/kWh, which is not bad for 24/7 clean power without storage.
Even things like electricity and water, which move pretty well, have "place value" -- people commonly move water from place to place by growing grain with the water and then moving the grain (not the water) to places that don't have enough water to grow the grain conveniently / economically. The same goes for electricity -- Iceland exports refined metals which require huge amounts of electricity to melt, effectively exporting the electricity entombed in the refined aluminum.
What can be made in space that can allow moving this abundant energy? Obviously you can't haul ore up into space then refine it with a big magnifying glass and drop it back onto the earth. People talk about asteroids but they seem like they're a big delta-V away from where they'd be useful to put into Kia bumpers.
I think bottom line is that resource utilization from space on earth makes zero sense. Space resources utilized in space makes perfect sense but there’s the chicken and egg problem. Bezos focus on space colonies fits this agenda. Musk mars colonization focus does as well due to mars low gravity.
There's probably a whole world of manufacturing processes that benefit from low gravity. The only one currently used is making high-quality optical fiber: producing ZBLAN fibers in 0g fixes a lot of problems with bubbles and crystal formation, allowing you to make better and much longer fibers. As access to space continues to get cheaper we will probably discover a lot of other cases where 0g is beneficial for manufacturing, and entombing energy might be another way to make those economically interesting.
Moon bricks. Ship regolith and dust into orbit from the moon, mix with water to make a moldable clay, form into bricks, bake inside the mother of all solar kilns and then drop them down on Earth. The water should be recoverable if the kiln is air tight. This would greatly reduce fuel needed on earth for construction. You could even make the reentry vehicle out of baked clay, only parachutes would need to be added. Extra points if you can make the whole thing buoyant and land them in the ocean.
George Crabtree et al from Argonne national lab are working on an automated chemistry lab that synthesizes and tests various flow battery chemicals on its own. Of course simulation and AI are used too but it's not enough. There are a lot of alternatives and a lot of different requirements / dimensions.
Very fascinating video: https://youtu.be/yv_8xfwsKxE?t=1208
If you need extensive industrial infrastructure in orbit, maybe make that from resources mined from asteroids. Ship high value finished goods down from orbit.
How much of that high value stuff will wind up in satellites? Cut the trip down the gravity well and just build in orbit, especially low value items that are expensive to launch but cheap to make.
So largely I believe the plan is to use microwaves to send the power back to earth so you don't have to have anything processed in space. This would usually involve ground stations that would receive the power.
Right -- microwaving the ground is just moving the energy, which may or may not actually be efficient. On the face of it it seems silly, but so does making a rocket out of water towers and landing it on it's ass on the moon, so I've re-calibrated 'silly'.
Nevertheless -- finding ways to move refined products around that embody a huge amount of energy is the traditional way to approach this problem.
And anti-matter, if you could package it, is an obvious example....
One problem with this that wasn't as much of a problem in the 1970s is RF interference. The 1970s designs and many other designs use 2.45 GHz, so it will interfere with wifi and bluetooth, with bluetooth being more sensitive to interference.
How far does this interference extend? Thousands of kilometers from the receiver[0, see page 250]. Because the transmitter is far, the beam spreads out quite a bit due to diffraction and because the transmit power is gigawatts there's hundreds of megawatts of stray power. Making bluetooth headphones and bluetooth low energy tags work worse will probably make people angry.
Different frequencies could be used, but that requires allocating spectrum, which is a pretty difficult task politically. In the US, there are a couple bands in the sub-10 GHz range where power beaming works best that have few users. So it's not impossible, but still politically difficult.
I bet the military would love/hate it (depending where deployed), because all that stray illumination would make for a perfect bistatic radar source. Suddenly many radars can be passive, and stealth techniques take a serious hit.
I know super narrow notch filters up in the gigahertz are difficult, but has anyone thought at all about how narrowband the power transmission could reasonably be? Because then at least notching would be possible to squeeze out adjacent spectrum.
There are techniques. And generally speaking the bandwidth can be much narrower than the sort of things designed back then. Even a lot of modern systems are designed with less than state of the art tech for various reasons… reliability, cost, etc.
I loved concept art (like the NASA/Boeing illustrations that accompany this article) until the artists started to go digital/CG in the 80's or whenever it was.
I'm not a huge fan of the artist(s) depicting space concepts in this particular article though (still better than most rendered art). I tried to do a bit of googling to find something better but in 10 minutes the best I could come up with was this site: https://www.kuriositas.com/2013/08/space-shuttle-concept-art...
I think there was more dynamism in the pre-CG concept art, often a bold use of color, sometimes an exaggerated use of shadow/light.
This idea never made any sense to me. Why the heck would you spend billions of dollars to launch solar panels into space to gather sunlight then beam it to earth when you could just wait for the sunlight to get to earth naturally for free...
Yeah, no night, no atmosphere, constant power output, lot's of real estate, and panels in space do not need heavy superstructure to withstand weather or gravity, thus they could potentially be extremely light for the area (micrometers to tens of micrometers thick at most needed for light absorption). And in far future, if they are built of materials taken from moon or meteorites, you could also bypass most of the lifting cost for even that. Of course, that would need huge scale to justify the R&D to pull it off.
Anyway, space based solar power is the end game. Nothing on earth will ever provide the quantities of power (not even nuclear, fusion or fission) that capturing solar energy can.
Worth noting this isn't as much of a benefit as it's made out to be.
If you were designing a perfect power source, it would match demand, so produce more in winter in polar regions, and more in summer for regions with lots of AC. Similarly, you'd generally want more power during the day than at night.
This is part of the reason a mix of solar and wind that varies by latitude is an ideal mix.
Space power might get more bang for buck if it could target its power to different regions e.g. swapping from north to south as the seasons change, and/or following the day/night cycle and/or weather to maximise energy price.
> They could potentially be extremely light for the area (micrometers to tens of micrometers thick at most needed for light absorption).
This is really the key, if you can make a solar panel that’s as light and thin as say mylar, and then unfold it when you get to space, we could put up several kilometers of solar panels without requiring much mass at all. It’s not like there’s wind or rain up there to wear it down.
No night? Where are you putting these satellites? The only orbit that doesn't eclipse is sun synchronous, an already crowded orbit. Even GEO satellites experience eclipse.
The loss from the atmosphere is not the issue; plenty of energy still hits the earth while the sun is out, plenty of methods of capturing it (solar panels, mirrors to focus the heat, etc), the issue is that someone actually has to build it and it goes off at night. That, and transport.
The fact that a powerful microwave beam shooting precisely from the orbit is also a weapon platform (if directed outside the receiver) might have played some role.
Possible but highly inefficient for power generation. Need massive amount of mirrors with pointing + stationkeeping. For medium orbits will need a huge amount of receiver sites + beefy prop & pointing systems. For Geo will need a truly staggering amount of mirrors + sophisticated focusing + massive receiver sites on the planet. Anywhere you point the beam will have massive ecology / weather disruptions... Probably not suitable for human habitation in a huge area due to atmosphere dispersing the beam. See https://en.wikipedia.org/wiki/Space_mirror_(climate_engineer... for more info.
One cool thing we could do is slightly boost the amount of sunlight northern latitude cities receive. This will make solar panels there more viable and will make cities far more livable in the winter season. This could also be done seasonally. This is a cool example https://www.theguardian.com/world/2013/nov/06/rjukan-sun-nor...
Solar panels drop efficiency the warmer they get; focusing more sunlight on a space will heat that up.
There's solar heat based power stations, using mirrors that focus light on a point or a pipe to heat up oil; the question there is, would they become more effective if they get more light?
1 square meter of ground currently receives 1370 watts of energy (if my quick google is accurate); if this can be captured, you can do a back of the napkin calculation of how much you need. It's already been posited that filling a relatively small patch of e.g. a desert can fulfil all of europe's energy needs - no space things needed.
I like the idea, but there are a few questions I have for the plausibility of this approach. 1. Does mylar (or weight equivalent have enough reflectivity and flatness) to target a ground station? 2. How much light can be concentrated before becoming a risk (e.g., birds above solar panels, human eyes in vicinity)? 3. How fast will the mirror material degrade from solar wind and micrometeorites?
I assume someone has considered this scenario previously, but I imagine that SpaceX lift capacity and price might change the economics.
This was an energy generation option in Sim City 2000 with the caveat that occasionally the ray of microwave energy would "miss" and cook some of your city.
Has anyone updated the economic feasibility studies based on using SpaceX's Starship as the heavy-lift reusable launcher? At first glance, it seems like this, combined with today's greatly improved robotics and ion thrusters to move components from LEO to GEO, may be the key enablers.
Musk is on record saying it's a complete non-starter. There are all sorts of problems with it. Beam spreading is a huge problem, the ground receiver would generally have to be about 10x the diameter of the transmitter and these would need to be really big arrays. A 1km transmitter is ballpark. Targeting the receiver is tricky as even minuscule angular offsets mean you would miss completely. Losses from transmission and reception are huge, and the enormous emissions leakage means you have to clear the big chunk of orbital 'real estate' of other satellites or they'd suffer serious problems.
People sure put a lot of weight on an off-the-cuff comment Musk made in 2012, before Starship was even a gleam in his eye. That was the same year NASA published their SPS-ALPHA study[1] on modern SPS design, so Musk may not have been aware of it.
Modern designs use a phased-array transmitter, and a reference signal from the ground for targeting. Overall energy loss is 40 to 60% according to the book The Case for Space Solar Power.
It's probably the lower cost of earthbound solar and batteries that are the bigger factor in updating the feasability, trending in the opposite direction.
Readit News
and the study itself: https://www.nasa.gov/directorates/spacetech/niac/2011_Practi...
A book-length treatment of modern SPS designs is The Case for Space Solar Power. It has detailed cost figures but was written before SpaceX had accomplished much, estimating a cost at gigawatt scale of 15 cents/kWh. I plugged in Starship launch costs and it came to 4 cents/kWh, which is not bad for 24/7 clean power without storage.
What can be made in space that can allow moving this abundant energy? Obviously you can't haul ore up into space then refine it with a big magnifying glass and drop it back onto the earth. People talk about asteroids but they seem like they're a big delta-V away from where they'd be useful to put into Kia bumpers.
It's possible to grow extremely high quality crystals in microgravity, so there's your semiconductor and optics industries.
Bulk metallic glasses are easier to make in space for the same reason: crystals grow more slowly, and are easier to prevent.
High quality vacuum on a scale never seen before for experiments and industrial processes.
Imagine building the James Webb Space Telescope without needing to harden it against launch forces.
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Nevertheless -- finding ways to move refined products around that embody a huge amount of energy is the traditional way to approach this problem.
And anti-matter, if you could package it, is an obvious example....
How far does this interference extend? Thousands of kilometers from the receiver[0, see page 250]. Because the transmitter is far, the beam spreads out quite a bit due to diffraction and because the transmit power is gigawatts there's hundreds of megawatts of stray power. Making bluetooth headphones and bluetooth low energy tags work worse will probably make people angry.
Different frequencies could be used, but that requires allocating spectrum, which is a pretty difficult task politically. In the US, there are a couple bands in the sub-10 GHz range where power beaming works best that have few users. So it's not impossible, but still politically difficult.
[0]https://ieeexplore.ieee.org/document/9318744
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I know super narrow notch filters up in the gigahertz are difficult, but has anyone thought at all about how narrowband the power transmission could reasonably be? Because then at least notching would be possible to squeeze out adjacent spectrum.
I'm not a huge fan of the artist(s) depicting space concepts in this particular article though (still better than most rendered art). I tried to do a bit of googling to find something better but in 10 minutes the best I could come up with was this site: https://www.kuriositas.com/2013/08/space-shuttle-concept-art...
I think there was more dynamism in the pre-CG concept art, often a bold use of color, sometimes an exaggerated use of shadow/light.
Anyway, space based solar power is the end game. Nothing on earth will ever provide the quantities of power (not even nuclear, fusion or fission) that capturing solar energy can.
Worth noting this isn't as much of a benefit as it's made out to be.
If you were designing a perfect power source, it would match demand, so produce more in winter in polar regions, and more in summer for regions with lots of AC. Similarly, you'd generally want more power during the day than at night.
This is part of the reason a mix of solar and wind that varies by latitude is an ideal mix.
Space power might get more bang for buck if it could target its power to different regions e.g. swapping from north to south as the seasons change, and/or following the day/night cycle and/or weather to maximise energy price.
This is really the key, if you can make a solar panel that’s as light and thin as say mylar, and then unfold it when you get to space, we could put up several kilometers of solar panels without requiring much mass at all. It’s not like there’s wind or rain up there to wear it down.
Of course, there are loads of problems with the idea but I can see why it's intuitively appealing.
With modern modular designs using phased array transmitters, even getting that much focus requires a reference signal from the ground target.
Really though I don't see this scaling to energy production for the masses due to the beaming logistics.
It'll mainly be used to recharge drones that never land and possibly fry enemy systems / missiles / etc.
One cool thing we could do is slightly boost the amount of sunlight northern latitude cities receive. This will make solar panels there more viable and will make cities far more livable in the winter season. This could also be done seasonally. This is a cool example https://www.theguardian.com/world/2013/nov/06/rjukan-sun-nor...
There's solar heat based power stations, using mirrors that focus light on a point or a pipe to heat up oil; the question there is, would they become more effective if they get more light?
1 square meter of ground currently receives 1370 watts of energy (if my quick google is accurate); if this can be captured, you can do a back of the napkin calculation of how much you need. It's already been posited that filling a relatively small patch of e.g. a desert can fulfil all of europe's energy needs - no space things needed.
I assume someone has considered this scenario previously, but I imagine that SpaceX lift capacity and price might change the economics.
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Modern designs use a phased-array transmitter, and a reference signal from the ground for targeting. Overall energy loss is 40 to 60% according to the book The Case for Space Solar Power.
[1] https://www.nasa.gov/pdf/716070main_Mankins_2011_PhI_SPS_Alp...
https://spacenews.com/nasa-to-reexamine-space-based-solar-po...
https://www.esa.int/Enabling_Support/Space_Engineering_Techn...
https://spaceenergyinitiative.org.uk/
https://www.spacesolar.co.uk/
https://www.solarspacetechnologies.com.au/
Here's a nice recent summary (despite the publication date):
https://aerospaceamerica.aiaa.org/features/harvesting-sunlig...
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