All you need to know about space based solar power

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Solar power is a nice idea. Except for the issue with the clouds. And the nights. So, how about we instead put solar panels up in space and then beam the energy down? This futuristic idea is known as “Space Based Solar Power”. It’s been around since the 1960s, but in recent years several nations have launched projects to make it reality. I think they’re not kidding. Space-Based Solar Power is about to become a real thing. But how is it supposed to work? Is it a good idea to beam energy down from space? What are the pros and cons? That’s what we’ll talk about today.
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00:00 Intro
00:41 Who is working on it?
04:24 How does it work?
09:08 Pros
10:07 Cons
13:12 Summary
13:54 Learn More about Solar Power With Brilliant
#science #tech #quizwithit

[@SabineHossenfelder]

This video comes with a quiz that you can take here: quizwithit.com/start_thequiz/1687730777328x298369257241124300

[@jamesfunk7614]

In the 1990s, a SimCity game, IIRC, had a scenario in which the player had to help a city recover from several fires. The premise was something caused the microwave beam from a space based solar satellite to miss the receiving antenna.

[@defenestrated23]

That "zzztt" sound has lived rent-free in my head for 25 years

[@oohwha]

Plot twist... Kain setup a Tesla Coil secretly and that's what actually caused the fires...

[@Globovoyeur]

At least it wasn't a laser beam aimed at California...

[@pariah_carey]

And then, 20 Years later, a Lady would get removed from her Congressional Committees (and summarily labeled an Antisemite), for writing a Post on Facebook suggesting that the Same Thing might be responsible for the California Wildfires. 😂

[@jasoncarswell7458]

I was thinking the same thing! The microwave solar plant was very eco friendly, with no downtime and great efficiency, but I guess Maxis felt they had to give it a catastrophic accident so if the main collector dish out in space got misaligned it would drag the beam all over the city and light it on fire. Even as a kid I was like "Okay, just built it in the desert."

[@GamingDemiurge]

I agree with you Sabine. Looks not feasible with current technology and infrastructure. But someone is gonna make some juicy money making useless prototypes.

[@vytah]

That someone is currently busy running Twitter

[@madshorn5826]

A lot of "solutions" are short term scams to secure investment. Could we concentrate on boring old solar and wind that ia cheap(ish) and has a proven track record please?

[@iivin4233]

Intelligent people disagree with her for what it's worth. kzbin.info/www/bejne/m3Omk5eKna59hKc kzbin.info/www/bejne/bnOVmqSfgMqbr68 kzbin.info/www/bejne/jV63eoaJq7djgpY The reason I included the middle video is that even if the math doesn't work with rockets, as suggested in the first video, active support structures would change the situation completely.

[@MattCasters]

​@@iivin4233 it's like Sabine is jumping on every opportunity to bash green energy production with the single argument that the sun doesn't shine at night. Imagine working for decades on this very interesting problem of balancing the grid, only to be outdone with this single argument that nobody else thought of. Sigh. If only someone or some company planned to lower the cost to space by a few hundred times. That might allow solar production in space. But that might be a pipe dream, just like green energy, storage and balancing grids. Oh well.

[@schrodingerscat1863]

That seems to be what climate change is all about. Converting tax money into corporate profit.

[@danielhuber494]

In the early 1990s, I worked on space power beaming for the US DOE. There were two approaches microwave and laser array power transmission that were built and tested. I worked on the laser array collector panels. The entire transmission included laser array with wavelengths in the red and specifically tuned solar cell arrays to match the lasers. Earth based demonstated efficiencies of the system included laser diodes array efficiency better than 50% and monochromatic solar cell collector efficiency around 65% for a combined efficiency greater than 32%. Microwave power transmission systems were also demonstrated with conversion to microwave power at up to 65% and lower microwave receiver conversions.

[@nostromog]

The first thing I thought when I heard that the British proposal ground station has a surface of 87km2 was to think about what if we just take those 87km2 and fill them with solar panels? This would amount to ~17GW nominal, i.e. 6 times more than their proposed 2GW (at ~200W/m2 and the standard 10^6 m2/km2). The production in a typical weather would be (UK has ~1400 hours of Sun per year, Spain has ~3000) from 20 to 40 TWh. This is the power of ~15 power plants, and the production of 2 nuclear power plants in a good year. Also, the estimated cost of ~16billion£ enables us to build a couple of those Earth-bound power plants at least.

[@jasony8480]

I agree with your math, however I think too many assumptions are taken. Current statistics has UK with around 14 GW of solar power installed as of the end of 2022 (I see multiple numbers on it) and generated a bit over 13,000 GWh in 2022. This trend has generally proven true year over year. This would indicate that the actual generation of your proposed array in the UK would be around as many TWh as GW installed, so 17 TWh. While the space based array is super theoretical, with minimal real data to base off of, it would be reasonable (probably?) to say 95% of the hours in a year the array is working at full capacity (8760*0.95=8322 hours). This means that 2 GW for 8322 hours turns into a bit over 16.5 TWh. They would be roughly equivalent at power generation. Space solar has theoretically flexibility to power nearby space objects, which can let humans do cool and innovative things in space via powering manufacturing and less payload dedicated to energy, while the ground based solar WILL be cheaper. I view the space solar as a first step to space infrastructure and would necessitate advances in autonomous construction and maintenance. All of these will have massive ripple effects over the next few decades. That space solar is approaching cost effectiveness with its least valuable possible function, powering Earth, is pretty impressive. I would much rather the power be going to some space factory making super amazing crystals or leveraging unique weightless/vacuum environment to make terrestrially impossible high-value components crazy easily for the next generational leap in materials advances. Making the equivalent of a nuclear power plant in space for 18 billion primary western currency units is massive, just like the inevitable cost overrun. Maybe Space X will save it.

[@Reinturtle]

I love how about the most complicated part, the transport of energy, they basically say "I'm sure we'll figure it out later" 🤣🤣🤣

[@jay-em]

Is only physics, in sure a few laws can be broken.

[@Jesus.the.Christ]

It's been figured out for a while, but is actually a big problem that Sabine didn't mention. This Wikipedia page has all the basic info: en.wikipedia.org/wiki/Space-based_solar_power

[@cleitonoliveira932]

People will just boil water with a laser beam and then harvest it from here.

[@benjaminfranklin329]

@@cleitonoliveira932 yes, lasers are notoriously very efficient...

[@benjaminfranklin329]

It's easy, we just run a space elevator made from some conductive material... Now we just need to figure out how to support the weight of the cable.... 🤣🤣🤣

[@adrianflo6481]

Remarking on the difference of advantage and "not being a disadvantage" is primarily the reason i watch Sabine. Just analyses it ever so slightly more and precise than everyone else.

[@05Matz]

Good overview. One quick point: The receiving antennas can be wire mesh, from what I know. They don't have to be solid. Which means you can still grow your crops UNDER the antenna, as long as you don't run your tractor into the poles that keep the mesh up.

[@pwnmeisterage]

Have you seen microwave receiver dishes on cellular towers, communications relays, satellite TV? They're always parabolic dishes with solid surfaces. More surface area means more power/signal received, means more efficient energy collection from a transmitter source. I've never seen a microwave antenna array which looked like empty mesh.

[@05Matz]

@@pwnmeisterage I'm pretty sure very large dishes (radio telescopes, some old satellite transmitters more than 1m across, etc.) are often mesh. I thought it was only small dishes that needed to be solid?

[@andyalder7910]

@@05Matz Even small reflectors can be wire or mesh, look at the back of a TV aerial. The rectenna is proposed to be an array of half wave dipoles (wire rods) with a steel mesh reflector underneath. Sea based version 75-80% optical transparency, land based version will allow farming underneath.

[@mbak7801]

@@pwnmeisterage Mesh antennas are quite common as long as the holes are not too large it is not an issue.

[@gusmueller4413]

@@pwnmeisterage at 2.5 GHz, a one-inch steel mesh is optically identical to a solid sheet of steel for the same reason that polishing imperfections smaller than a wavelength of light are invisible on a mirror. the wavelength of 2.5 Ghz is 4.7 inches.

[@maxwellblackwell5045]

I had this idea when I was 16. My astronomy teacher (who graduated mit with an aeronautical engineering degree) told me it wasn't practical for many hundreds of years unless we get a massive leap in technology. He explained why perfectly. This was around 2005.

[@DesertRat332]

Peter Glaser wrote papers on SunSats in the late 60s (1968) and received a patent for transmitting via microwaves in 1973. He retired in 2005.

[@ogi22]

@@DesertRat332 Seems like we are in times where leaps of technology are pretty constant. Just take a look at an old idea about the detonation engine. I just had a similar talk with my co-worker. I think that Chinese curse is getting us - may you live in interesting times😉

[@bozo5632]

He was probably wrong about the "hundreds of years" part.

[@maxwellblackwell5045]

@@DesertRat332 wow. That's a crazy coincidence. Thank you. I didn't mean I came up with the idea in a vacuum. I probably saw something similar in an Arthur c Clark novel. I read most of his works. Either way I don't think I saw it directly but I also didn't come up with the idea out of thin air.

[@maxwellblackwell5045]

@@bozo5632 probably. In the early 2000 I was told a lot of things we have now would be impossible. I was also told we would have rings we now know are not likely to have any time soon. Hit or miss with tech predictions.

[@thevaf2825]

Engineer: "...and we'll use microwaves or lasers to transmit the energey back to the surface of the planet." General: "yes yes, to achieve net zero. Please take my money and give me your laser cannon..ahem..space power plant."

[@faustinpippin9208]

hahaha yep, the only reason they consider this is because of the military, but as a bonus they use money that was supossed to go for real useful projects

[@sophiophile]

I think you meant rectifying antennae, not receiving- as in it also converts the induced AC by the EM radiation into DC power.

[@hoon_sol]

Rectennae are used to receive the radiation.

[@robwhythe793]

As a safety engineer, I was waiting for the time you raise the issue of what do you do when the energy beam goes astray from the target area and burns down anything nearby. It never came. The discussion was entirely on whether it can be made to work effectively and efficiently, assuming everything works properly. As an engineer with a background in transport generally, and aviation in particular, I am always looking for things that can go wrong and making sure there is at least one redundant system to take over when (not if) it does. And, for historical purposes, I remember one of the short stories in "I Robot" by Isaac Asimov, based around such an energy beam which had to be tightly controlled and not allowed to go astray. It involved the robots assigned to target the beam developing their own religious understanding of why they were there and what they were supposed to be doing...

[@MT-xu7dh]

This isn't an issue. The beam is kilometers wide so it has a very low energy density. It won't burn anything.

[@danilooliveira6580]

she literally said the energy is 10x less per m^2 than sunlight and only in the form of non-ionizing radiation. its less than being close to a 4G antenna.

[@sarahrosen4985]

And yet, anything that can do wrong will go wrong. I’m with you: safety and redundancy features for alllll the things everyone says not to worry about.

[@meesalikeu]

it was totally made. its like a microwave oven or cell phone beam, not a war of the worlds death ray. you wont die, you would just grow an extra arm and a few tumors.

[@takanara7]

@@MT-xu7dh In that case you would need a kilometer wide receiver, otherwise you're just wasting energy. So what even is the point? Just put the solar panels on the ground and save a ton of money.

[@charlesspringer4709]

I remember well some excitement over Gerard O'Neil's powersat and space colony initiatives. Both were premised on Lunar based manufacturing with electromagnetic mass drivers to put materials into lunar orbit. The major objection was a wandering Supervillain beam. But the rectenna sends feedback to the transmitter (a large phased array) to maintain beam coherence. Without the feedback the coherence collapses and the beam becomes very broad. Thus, no death ray. The idea was that by making a lot of these, the Moon based source is cheaper and easier in many ways than the Earth based production. For one, you don't need rockets and reaction mass because you can basically launch horizontally with electricity. And the upkeep and replacements don't depend on launching through the atmosphere and this deeper gravity well.

[@Hallo1248574]

I think the real military application would be concentrated microwave beams destroying ground targets. The first orbital energy weapon. Reminds me of the orbital particle cannon used in the X-files.

[@methylene5]

We call it renewable energy, the government calls it "Project Goldeneye".

[@0masuk0]

They are too vunerauble for that. Use it to charge drone and China or Russia won't escalate by shootng your sattiletes out of space. Use it to shoot things (and this goes agains internationa agreements on demilitarization of space btw) and your 10bln thing goes down.

[@obsidianjane4413]

Not really. An array powerful enough to have kinetic surface effects (ie "deathray") is different enough from what is needed for commercial power transmission that international eyebrows would go up. Even concentrated mazer can be defeated with nothing but mylar and conductive mesh grounded to earth. Commercial is spread wide enough that it would be more uncomfortable to be hit by it than dangerous. A military mazer relies upon heating up a sympathetic material (vegetation, water, some rock) to the vaporization point, causing it to explode for blast and fragmentation .

[@methylene5]

@@obsidianjane4413 You know an array could be designed to act also as a focusing mirror, right?

[@obsidianjane4413]

@@methylene5 And that would be the "different enough from what is needed for commercial power transmission..."

[@cmilkau]

Lol, proof by citation. I remember a group of authors doing that when researching for my graduation thesis. They referred an earlier paper as a building block, which somehow managed to refer to the later paper as a building block (both appeared within a few months of each other). Now this wasn't without value as those building blocks can be provided later independently, however claiming "achievement" of a technology is a bit of a stretch (no, it's an outright lie) in that situation. Funny enough, one of the two technologies was achieved independently about the same time and the other turned out to be if no other use, so these papers are basically redundant now.

[@jamesfunk7614]

Reminds me of XKCD 978

[@alanhat5252]

@@jamesfunk7614 you've got a long memory! That was 2011

[@simongross3122]

House of cards?

[@cmilkau]

@@jamesfunk7614 Only that these guys accelerated the process by citing themselves

[@Yerrt87]

I found your channel through PBS’s video on Superdeterminism. I rarely leave comments, but I felt inclined to thank you for doing amazing work. I look forward to continue watching more videos. They have very well articulated arguments!

[@LyceanEM]

Nice to hear the summary, especially as working out if we can make the long distance beamforming practical is one of my jobs now. The antenna arrays required will be the largest ever built by 3 to 4 orders of magnitude.

[@MehmetSurmeli]

I burst into laughter many times, particularly that particle physicists spin-off joke was hilarious. I love your sarcastic cool intelligent humour.

[@alandenniston7992]

Sabine could teach the British a thing or two about dry humor. Hilarious.

[@danielmcwhirter]

One of your videos on greenhouse effect said infrared photons have a thirty meter mean length of travel in the atmosphere before scattering or absorption. Thus I was shocked that my infrared thermometer measured the sun at about 450 F and clear blue sky straight up as low as -8 F. The temperature of blue sky warms quickly to the teens as I scan away from vertical. Low clouds (a few thousand feet up) measure just a bit lower than ground (64 F versus 68 F) atmosphere. Cirrus clouds and contrails' overcast ran around 40 F.

[@psycotria]

... and 98+% of the "Greenhouse Effect" is caused by water vapor, a thing impossible to blame stupid humans for.

[@Dowdyguy]

I love Sabine's presentation! Her videos are highly entertaining, and almost understandable!

[@Brucebod]

Ha 😄

[@Lucius_Chiaraviglio]

I can see a problem for the proposed military applications: The microwaves that are scattered off the intended recipient or that miss and are then scattered off the ground will be a huge "SEND MISSILE HERE" sign for the enemy, even if the enemy has only moderate technical capability. As for civilian use, I think the cost estimates are being lowballed -- it is hard to see how sending to orbit thousands to hundreds of thousands of solar panels (and as noted, having to maintain them up there) would be cheaper than just building twice as many solar panels and/or the equivalent in wind turbines plus energy storage systems on the ground.

[@tayzonday]

Aren’t wind and hydroelectric power technically just kinetic derivatives of solar power’s entropy? They would not happen without the sun. Places like the UK can just access “solar power” through a different vector.

[@tedarcher9120]

Oil and coal are as well, just very old solar energy

[@JohnCena8351]

I love that KZbin classics like you are here.

[@tayzonday]

@@tedarcher9120 I’m also just thinking that the UK is surrounded by tides moving more mass than every electrical turbine on Earth- also solar energy cause the moon would not perturb frozen oceans. Beaming that energy down from space seems impractical 🤷‍♂️

[@artemonstrick]

if only wed be able to build chocolate rain collectors and chocolate power generators, our problems would be gone forever!

[@skylark8828]

@@tayzonday There are already UK projects that harness the power of motion within the seas but they are expensive, need maintenance because anything left in there for long will get covered in cr*p and seize up, and could also be detrimental to ocean ecosystems (eg. noise pollution, fish killed by blades/turbine parts etc).

[@zappababe8577]

When naming something just to get a cool acronym, there actually is a word to describe this - it's known as a "backromyn" which I think is very apt!

[@FTZPLTC]

I thought backronyms were acronyms that are made up afterwards - like "Port Outward, Starboard Home" as a fake etymology for the word "posh".

[@gilbertanderson3456]

​@@FTZPLTC A word used as a memory aid to facilitate recollection of a phrase is known as a mnemonic (pronounced nemonic). A backronym is an acronym created "after the fact", where the name comes first and may be widely known and later a phrase is created from the letters of the name which elucidates the goals or methods of a named project or the instrumental capabilities of a named space probe or astrophysical research project.

[@FTZPLTC]

@@gilbertanderson3456 Yeah, I think I was thinking of "backformation".

[@GodofTrek]

The size requirement of the receiver is probably the deal breaker. Also, those cost estimates seem like they are JUST for the solar array, and not also the receiver array? For the required cost and space, you could just build a few large farms and a Nuclear plant to get a better overall result.

[@derekgarvin6449]

Excellently done. Thank you for including the feasibility and costs so that the tech can be looked at as a business decision.

[@dgkimpton]

I think it's highly unlikely to be an efficient solution (which almost guarantees someone will build it) but placing the ground arrays out in the ocean or on an uninhabited atol somewhere could alleviate a lot of the NotInMyBackyard concerns (ignoring, of course, the minor issue of the extreme cabling challenge). We could probably better invest in some new reactor types though.

[@lombas3185]

Or you could just put the power plant in the moon and make a base there after that. It should be way cheaper to make and maintain than the alternative (only after putting pads in the moon for them not to break on fall first), and we could use that power to mine and make rockets or something like that to bring materials back. Maybe the whole project would be too expensive to make, but once done it should be a nice way to earn easy money

[@QwoaX]

The problem with new reactor types is that with the development, bureaucracy and build time and with all of the material being used, they will take decades to build and will take even longer to actually reduce our carbon footprint. By that time, we are either at least carbon neutral anyway or we face dire consequences.

[@falloutfan2502]

That was my idea too! Pick a spot like Midway Island, and beam away. Make a study about it, and whether it hits the ocean around it, etc. Don't find out in 20 years that you gave everyone cancer. Have a base station there, and run an undersea cable to Hawaii or something just for proof of concept. Also, why no Dyson Swarm around the sun, relaying energy to equatorial geosync relay satellites? Efficiency, sure, but much more power to be gotten nearer the sun, and less junk in Earth orbit.

[@paulie-g]

We don't even need new reactor types. Russians have cheap 3G+ reactors they can build reliably on time and on budget. They'll have an experimental-production closed loop for irradiated fuel in less than 10 years and full-production in 20. Job done. Except EU/US education is now so terrible that they're afraid of fission because it's black magic.

[@Jesus.the.Christ]

Jesus Christ 0 seconds ago The power can be beamed down to farmland. The rectennas can be placed over fields and don't have to block sunlight (the rectenna is not a wall, it's more like a fence). The rectenna stops the microwaves by absorbing them so they don't reach the ground. So where you place the rectenna is not a problem, farmers just need to accept that they've got a new revenue stream.

[@thekeytoairpower]

IIRC (and a short google tells me I do) Asimov predicted this tech in his short story "Reason", that was eventually published as part of "I Robot". One of my favorite stories.

[@quillaja]

Yea, that was a fun story. =) "Liar" remains my favorite, though, because of its drama with Dr. Calvin and the ties to later novels.

[@thekeytoairpower]

@quillaja if we are talking all tome favorite Asimov short stories it is "The Machine that Won the War".

[@morriewyatt6234]

My favourites are "Robot AL76 Goes Astray" and "Victory Unintentional" from "The Rest of the Robots".

[@kornenator]

I am quite convinced about space-based solar power. In fact, 100% of our solar power is space based already. Job well done, Sun!

[@jamesvandamme7786]

I have a fusion powered clothes dryer

[@carrotwine3649]

I like how Sabrine just puts possible military applications into pros column, damn, that would be fun

[@robertpearson8798]

The two biggest problems I see with using lasers for the energy transmission are 1- clouds and 2- the possibility that Dr. Evil might take control of it and demand ONE MILLION DOLLARS! There’s always a third option, using a space tether that doubles as an enormous extension cord.

[@jalvrus]

The other problem with space-based solar that you didn't mention is the problem you covered a few weeks ago: it will introduce more energy into the atmosphere than is currently going into it. So it's similar to nuclear in that regard.

[@Rob2]

It is not really energy introduced into the atmosphere by the system. Of course any energy you put into the grid is eventually ending up in the atmosphere, but that is true whatever method you use to generate it.

[@epajarjestys9981]

@@Rob2 You are making no sense.

[@BlinkyLass]

But isn't the energy from intercepted sunlight that would otherwise reach earth anyway?

[@toomanycharacter]

No, that doesn't make any sense. A solar station orbiting earth doesn't generate any energy, it just focuses the energy the sun already gives earth into a single beam. The earth would have received that energy from the sun anyway, although not in a single beam but lots of beams.

[@markwheeler202]

@@BlinkyLass No. It would take sunlight by day and by night, the latter being light that would miss Earth otherwise.

[@simongross3122]

Wouldn't we be better off just putting solar panels in desert regions and accepting the high cost for transmitting electricity long distances through cables? At least we could provide ground-based maintenance.

[@poulhenne]

Yes, that would be better, but you cannot make an optimistic space-race startup to milk Elons money with that. The obvious low hanging fruits are never great at attracting gullible investor money. And trying to fix our political shortcomings with a technical fix is just pathetic. You can see the ridiculousness of our politics when new houses are still being built with normal roofing. And some then choose to put PVs on top of that. What a waste.

[@simongross3122]

@@poulhenne All true. Obviously we're all too rich because we don't seem to care about the waste. I'm a bit outraged at the amount of waste generated by knocking down houses and dumping things like PV and roof tiles, when they can easily and profitably get a second life.

[@davidvergison5955]

I love your videos, the tone, the subjects, the explanations ... thanks !

[@jermsbestfriend9296]

Yeah, until she gets into social issues and lies like a dog.

[@jsalsman]

The narrowest half power beam width of a power transfer microwave beam is about 1.3 degrees. The rectenna from GEO would need to be literally the size of Puerto Rico.

[@Stevobulfer]

Ha I have a lot of friends working on this. I don't think most people think it's reasonable, but it attracts juicy grants. Thing is, there's so much technology that can be related to the project, that the development of those components is useful and worthwhile even if the whole project isn't necessarily worth it.

[@mellertid]

Yep, that's space tech in a nut-shell.

[@utkua]

Oldest excuse in the book when making useless things.

[@slolerner7349]

"What would happen if we ...?" makes some of the best science

[@brucesoluski6390]

Hi, The power stats will be built eventually. Refer to “The Moon is a Harsh Mistress”, but with AI robots not prisoners. Unlike US or Russia, India in neer the equator and it build a rectanna on the ocean. Maybe these robots can build you a telescope.

[@Stevobulfer]

@@utkua not saying it isn't useless, but billionaires are idiots and if sci fi bullshit is what it takes to get them to fund real science, I'm all for it

[@gaius_enceladus]

Sounds like a crazy idea. Much simpler and easier to get small modular reactors up and running.

[@amphibiousone7972]

THANKS Sabine, Totally agree 💯

[@Weissenschenkel]

I think the "military applications" would drive them to achieve the best results ASAP, even if the technology isn't feasible for commercial use in a near future. Thank you for sharing, Sabine.

[@hoagie911]

Every new technology proposal scrambles to put "possible military applications" on its profile, because that's a sure fire way of increasing your chances of getting funding. It doesn't mean any of those applications have to be feasible or useful.

[@dx-ek4vr]

That would be like something similar to the "Sun Gun", one of Nazi Germany's crazier proposed Wunderwaffen

[@olik136]

we will get our s̶p̶a̶c̶e̶ ̶l̶a̶s̶e̶r̶ death ray one way or the other 👍

[@Thomas-gk42]

​@@dx-ek4vr hope you're right, the Wunderwaffen didn't work fortunately, and the planet carries hard enough weapons.

[@schrodingerscat1863]

The size of the collector necessary to get power from these space stations would really make any military application very limited. Charging a drone for instance is a none starter. They could maybe direct the beam over an enemy and cook them I suppose.

[@HansLemurson]

"Sim City 2000" had Microwave Power plants, and even had a disaster scenario where the beam goes off target and tries to fry Silicon Valley, frying Highway 101, and burning down large portions of Sunnyvale and San Jose. I...may have played it again recently for nostalgia.

[@Mr.Mitch1111]

The humor, on the forms of sarcasm typically, is very welcome to stir up the otherwise raw atoms of illumination you can provide. Really appreciate that.

[@jasoncarswell7458]

I remember this from SimCity 2000. It worked great unless the primary collector dish got misaligned - then the focal point wandered off the secondary dish and burnt up parts of the city like ants in a magnifying glass.

[@epajarjestys9981]

@Cancer McAids SimCity it not a game but a simulation. It is realistic.

[@MarksElectricLife]

A scientist, an engineer and an entrepreneur walk into a bar… Scientist: “Hey we’ve discovered you can theoretically capture the Sun’s energy in space and beam it to Earth to power cities.” Engineer: “Yeah, but we did the math and the efficiency is lower than terrestrial solar and the high build cost makes it unviable.” Entrepreneur (to Scientist): “Great! How soon can you give me a slide deck to present to investors?” Engineer: “Didn’t you hear me? IT’S UNVIABLE!” Entrepreneur: “YEAH, I LIKE THIS DJ TOO! LET’S GET SOME BEERS 🍺!”

[@HamannGeorg]

"Don´t be so negative, see it as an opportunity." - Engineer leaves with rolling eyes Could someone pls bring back Engineers into decision making?

[@kindlin]

This is so true. The times I tell someone they can't do it and they go "Are you sure? Did you try X, Y or Z? How much does it REALLY cost?"

[@tony_mo]

8:29 summarizes it all, great image to get a sense of proportion and order of magnitude.

[@louschwick7301]

literally the plot to resident evil revelations. for some reason, the game also made it so that it needed to be received by a floating city off the coast of the levantine middle east, and that too much solar power somehow sank the city. it was a stupid game. somehow, that wasn't the stupidest aspect of the game

[@davidgrant9354]

Because the radiation is in the microwave region, say 3GHz frequency, one wavelength is around 10cm, so it should be possible to build rectennas that intercept the microwave radiation, but are mostly transparent to sunlight, wind and rain. So, mount the rectenna array ABOVE a field and grow crops under the array. Let the farmer farm his fields and give him a fee for use of the area above the field.

[@row4hb]

Don’t crops require sunlight?

[@riv1993]

The fee is exploitative and illogical. Resources should be owned by everyone.

[@britskaradiometeorograph8108]

​@@row4hb "...but are mostly transparent to sunlight, wind and rain"

[@davidgrant9354]

@@riv1993 ok, we’ll all move to your house and use your electricity for free :-)

[@vultureTX001]

@@riv1993 labor is a resource thanks for donating yours comrade.

[@dcmeserve]

I remember hearing of a proposal for a much more modest version: have a collection of mirrors in LEO that can reflect sunlight onto various “client” solar arrays on the ground as the satellites pass within sight of them. This would increase the irradiation those panels receive during the day, and/or extend their productive times several hours past sunset and before sunrise. This would require *much* less investment in space hardware, and allow for incremental deployment. It also eliminates the requirement for special ground equipment, and avoids mucking about with irradiating a landscape with microwaves.

[@user-xq8qx6bg2j]

❤❤Sabine, your quip about solar micro waved pigeon is coo and impeccable, as usual. Your sense of humor, sublime and out of this world. I think you are divine🌹🌹🌹🌹🌹🌹🌹😘😘😘

[@berfunkle4588]

I would have loved taken a a physics course with you as the teacher. Don't get me wrong, I'm sure I would have still gotten a "C", but I would have enjoyed it more!

[@kickinrocks6055]

It's okay. C is a constant.

[@classarank7youtubeherokeyb63]

They get degrees

[@marca9955]

Rectenna is short for rectifying (not receiving) antenna. Specially intended for remote power applications.

[@DesertRat332]

I can't believe you didn't mention Peter Glaser who worked for Arthur D. Little and wrote papers on Solar Power Satellites (SunSats). His work motivated me to go into Mechanical Engineering and to study hard in the hopes of someday working on such devices. I'm retired now, but I'm still thankful for his motivation, because I had a good life.

[@jamesvandamme7786]

How about Bill Brown at Raytheon?

[@digiryde]

Great overview of the issues. This has always been a fun concept, but the current practicalities in my opinion make this a no go.

[@pwnmeisterage]

Space-to-surface power transmission seems impractical and perhaps a dumb idea anyways. But space-to-space power transmission could be very useful. It would basically allow multiple, separate, replaceable, upgradable solar arrays to send energy to a structure or vessel in space, even if it's located (or moving) outside Earth orbit.

[@KNemo1999]

De-risking is a perfectly crumulent word.

[@CarletonTorpin]

I’m embiggened by your use of the word “cromulent”!

[@Bodyknock]

An interesting thing is that the rectennas that would receive the microwave beams and convert them to power function on a different frequency of light than solar panels do. So I wouldn't be totally surprised if it was possible to "overlap" a receiving area with a solar panel array so that you're getting double the use out of the land, assuming you're not just leasing farmland and paying the owners to let you have antennas there.

[@andyalder7910]

Sea based version 75-80% optical transparency, land based will let more light through.

[@kindlin]

For any of this to actually work, we need to up the efficiency considerably. The 87 sq km stated in the video is ridiq to ever expect to happen. Only getting 1/10th the sunlight's power, even if it is continuous and reliable, is not worth the cost over regular solar panels. Now, if we can get the beam forming quite a bit tighter, down to a couple square kilometers, then we can actually setup the MW antennas right over the solar panel farms (which can actually sit over some other kinds of farms) and only infringe on ~10-30% of the sunlight, depending on how efficient a microwave grid dish can be, I don't think this has ever been a design consideration until now. Many plants actually like a little shade, so this might be a perfect thing to double-up on on actual farmland, not solar farms, food and animal farms.

[@IroAppe]

Also, it only requires a loose mesh, spanned above the farmland. I think for the cost of a solar panel of 1m², you can span a mesh with much more area. And then of course, the added advantage: You'll receive that energy during cloudy days and during the nights. Compared to the complexity of a solar panel, I can see how you could probably get 10x the area of mesh with the same cost.

[@kindlin]

@@IroAppe I don't think our posts contradict each other at all. I even point at that the microwave system only uses maybe 20-30% of the available area, like your light mesh idea. Specifically, I see Grid Dishes get used pretty often, and to my point, these have never been designed with the intent of limiting cross-sectional area.

[@IroAppe]

@@kindlin Oh sorry, I actually replied to the wrong thread. Take it as an appendum then :)

[@herzogsbuick]

I remember building my first crystal radio sets as a kid in the early 90's, which taught me that radio waves carried energy. In elementary school, I had a notebook I kept my inventions in, and one of these inventions was exactly this. I dunno, I was in maybe 3rd grade. It had a satellite with solar arrays that beamed the energy back to a ground station. I can still see the ground station in my head. No idea where the notebook ended up. Just a fun trip down memory lane.

[@arkheavyindutries]

This was my favourite power station in Sim City 2000. Accidental wild fires would occur sometimes, though.

[@rogerfroud300]

It seems to me that if you spent the same amount of money on Earthly panels, you would get just as much energy, and without it being vulnerable to attack or Astral mishaps.

[@MusikCassette]

more, ... way more, ... we are talking orders of magnitudes.

[@Mallchad]

Not really, space based potential let's you build objects with virtually no structural integrity or mass (wafer thin solar reflectors) or any kind of heavy facility. It makes it much easier to build very huge facilities that isn't susceptible to constant erosion on the planet. Besides, I don't really like space based power for earth, the atmosphere makes it impractical and hazardous to use high energy lasers for efficient power transport... For the moon it would be great

[@Nosirrbro]

@@Mallchad you could just put the solar panels for moon power on the moons surface though

[@yakovdan]

except on earth, you need to add tons of battery storage, overbuild for weather, diversify geographically to improve reliability and invest in transmission lines. Sure, shaving off that summer daytime peak consumption in Southern California is easy. Slap on some panels and you're done. On the other hand, guaranteeing 24/7 availability in unfavorable climates is extremely difficult. Might as well solve that transmission problem and, at least, supply the last, most difficult 10% of power draw from space.

[@Mallchad]

@@Nosirrbro Not exactly... There are a of non-trivial issues with lunar solar power that's more manageable in space. Like for a start the moon still has a day-night cycle which means for 50% of the day you can't really use high energy machines. Like metal refineries and excavators and fuel refineries... Not hugely sustainable Also there is a preference of sending moon missions to the poles right now because of the ice for fuel and water, where there is much less sunlight. There's wild thermal cycling from lunar day to lunar night and dust damage and electric storms and high energy particles... It's not really any better than anything in space

[@tezer2d]

The video game SimCity 3000 had a "microwave power plant", but I always assumed that was just a joke. I didn't expect it to be a realistic concept that governments are actually trying to make real.

[@Danuxsy]

most sci-fi concepts are based in some truth.

[@nomizomichani]

Your profile picture is appropriate with your comment.

[@kaoskronostyche9939]

"Realistic concept" and "government" and "make real" in the same sentence should be the only tip-off you need. Ever seen or heard of those three coming together in a productive, efficient or realistic way? I haven't.

[@PaulPassarelli]

You asked if I would invest in it. My answer is a resounding "no." Needing a 100 year timespan to make the power cost competitive is why.

[@rickknight1810]

I'm pretty skeptical. The prospect of huge microwave beams coming from space scares the hell out of me. A nice collection of big "don't go there" locations. And if the thing goes haywire and points its beam in the wrong direction . . . it might lead to a bad news cycle.

[@greg4367]

Clarity as always Sabine, thank you. I would invest... not a single dime.

[@drecksaukerl]

Agreed. I'd rather "invest" in a day at the casino. At least I'll have fun losing my money.

[@subliminalvibes]

I agree with all your points Sabine. I think a Dyson structure around the sun equipped with a giant MASER would work. It could beam the energy to the moon for storage and a stable, accurate, fixed transmission down to earth for further storage and distribution. That reminds me, I need to go take my lithium tablets... Thanks Sabine! 👌😎🇦🇺

[@simongross3122]

Maybe we could create a huge ring around the planet in geosynchronous orbit to replace all the satellites. Then we could colonise the ring with people genetically engineered to survive there and perform maintenance for us.

[@ogi22]

@@simongross3122 Hehehe, Elysium? Hyperion? Too much SciFi 😁Now we just need to find the Time Tombs, Cruciform and let the AI develop into a TechnoCore 😆

[@simongross3122]

@@ogi22 Is there really such a thing as too much SciFi? Some of Arthur C Clarke's Science Fiction became Science Fact 😄 Anyway It's certainly more interesting than the Political Fiction we seem to get 😃

[@ogi22]

@@simongross3122 Hehehe, yup! I agree :D

[@FireAngelOfLondon]

@@simongross3122 A solid or liquid ring is not orbitally stable, so it would not stay in place without repeated boosts from rocket motors to keep it in place.

[@oldboi_gg]

I have been intrigued by this technology ever since I started following the CalTech Space Solar Power Project some years ago. Thank you Sabine, for clarifying the actual estimated performance versus a nuclear power plant. This makes it abundantly clear that we would be better off shooting the radioactive waste into space, rather than this immense effort just to obtain the power of a single nuclear plant. Correct me if I'm wrong, y'all.

[@TheKrister2]

9:16 I'd like to add to this a small asterisk. Even though the solution itself doesn't produce pollution, the process of mining the massive amounts of resources needed, building each individual part and yeeting it into orbit _does_. And I'm personally skeptical that this process will let things even out, if you don't go over a large period of time where you don't need maintenance (since that requires more launches). Considering then that they'd assume a hundred years of operation with maintenance to get it in the same ballpark of price-per-watt, I find that a rather big if as to whether the project will truly be net-zero. Edit: Fixed some spelling :(

[@philnelson9791]

I guess large scale, it's pretty crazy, for the near future. We have plenty of power down here, we're just not using it well, or at all in some cases. But it would be good to have around, for special cases, and to deal with surprises.

[@TaylerKnox]

Like what? The sun dies? Wind stops blowing? Batteries stop working? What surprise would justify such a costly project?

[@joeljong931]

It could be used in a cleaner lunar orbit with less orbital debris and power lunar stations and launch vehicles which is less risky than going to Mars.

[@philnelson9791]

@@TaylerKnox One thing which might happen is that we discover that the global warming hypothesis is wrong and are in fact in a situation in which it would be advantageous to add heat to the environment on a large scale. Another is that we might find it most effective to maintain solar power stations close to earth, for easy access, which do not direct power to earth, but to other objects, perhaps interplanetary transports.

[@philnelson9791]

@@joeljong931 I was multitasking, so I might have misheard, but, I thought mention was made of geosynchronous orbits. The problem of keeping the beam reliably confined to a small target on earth is more complex from other orbits.

[@joeljong931]

@@philnelson9791 perhaps a geosynchronous lunar orbit for powering moon bases or build a dark side of the moon telescope to monitor the solar system. In fiction there are many stories of hidden bases on the dark side of the moon.

[@picksalot1]

I think capturing tidal/wave energy would be a better solution. It is a huge cyclical oscillating mass that runs 24/7 for free.

[@0MoTheG]

Sadly it makes little power unless you build dams that destroy the ecosystem.

[@Geekofarm]

As the grid connection infrastructure would be in place at a receiving station, it would be a great place to put other renewable generation systems such as wind farms or conventional solar, though this would add relatively little extra power. For comparison a conventional wind farm generates 4MW/km^2 and the British beamed power proposal works out at 23MW/km^2

[@Poctyk]

> 4MW/km^2 The average capacity of newly installed U.S. wind turbines in 2021 was 3.0 megawatts (MW), Assuming 33% of it actually becoming electricity, that would assume that there are 4 turbines per km^2 They are big, sure. but 4 seems a bit low.

[@mickwilson99]

Nitpick: "rectenna" is actually shirt for "rectifying antenna", not "receiving antenna" as Sabine stated. The rectenna converts the oscillating em field of the microwaves to DC electrical power. FWIW I studied SBSP (then known as SPSS - satellite-based solar power) back in the 70s as part of my physics degree.

[@markmcdougal1199]

I wonder if someday when carbon nanotube production restraints are all ironed out, if we could extend a cable (similar to the space elevator idea) between the collector and the transmitter. This would solve the problem of microwave loss due to dispersion, as well as make the receiving station the size of a large building, instead of square kilometers. Aslo make maintenance a lot easier. IMO, this is the only solution that might make space based energy collection feasible. I'd love to see a presentation from you on this. As, always, love your vids, and you.

[@cmilkau]

But why? There are ridiculous amounts of solar energy coming to ground for free

[@Thomas-gk42]

My thought too, but when I heard, that an orbit of 36000 kilometers is nessecary, I buried rhat

[@ehrichweiss]

I'm glad you tackled this because far too many people only look at the pros and never consider the actual cost of the cons. I haven't yet checked to see if you have a video on the topic but I'm guessing you have seen a few problems with so-called "asteroid mining". I think it's a fine concept *IF* we aren't trying to bring them back to the surface. I mean, if we refine, etc. the materials and then build space stations, etc. then it makes perfect sense but people are talking about tons and tons and tons of stuff that has to come down here somehow and simple parachutes aren't going to do the trick really, nor is pointing it toward some spot in the ocean. Anyway, if you have not done a video on asteroid mining then please do. I'd love to see all the pros and cons spelled out so that I can point some of my overly optimistic friends in the right direction.

[@palladin9479]

Asteroid mining would be done remotely with drones and sending that material back to earth would be ... wasteful. Instead that material should be used in automated space construction. What you do is fly up and assemble the first small scale drone factory, then it goes out and collects material and uses that to produce more drones and more drone factories that then can be used to build stuff. It's a long term project that we most likely won't see in our life times but will be akin to the industrial revolution.

[@alanhat5252]

Felix Baumgartner proved that parachutes are good enough. Why spacecraft need heat shields & stuff is that they have tangential speed & it's cheaper to burn that off in friction than to carry fuel to reduce the speed.

[@epajarjestys9981]

I think she has done a video about asteroid mining long ago. Maybe it wasn't the topic of the whole video so might be hard to find.

[@grasstoucher8503]

@@cancermcaids7688 There's also the environmental cost to consider. Mining on Earth can sometimes be very environmentally destructive and lead to some awful pollution left for whoever may be living near the site to deal with. So mining off-planet might become an ethical necessity rather an economic one at some point.

[@pattheplanter]

Very easy to check with the search function. kzbin.info/www/bejne/iYrLlomQhrZ7js0

[@Zift_Ylrhavic_Resfear]

Thanks for the video :)

[@listerdave1240]

There seems to be a fundamental issue that every single study on the subject is missing, that is the losses in the RF feeders which will be interconnecting the elements in the multi-kilometer wide phased array antennas. When I say huge losses I don't mean you lose 50% or something of that order but that you will lose over 99% of the power received by the antenna, probably even more. In theory these could be avoided by using a dish antenna with point source illumination but good luck building a 15Km diameter parabolic dish down here on earth. Having multiple smaller antennas/converters won't work because to achieve the directivity the antennas have to form a single phased array. The whole idea is in principle unworkable unless someone comes up with a way to economically make superconducting waveguides. Something which might make more sense would be to use light in the spectrum between long infra red and near UV instead of microwaves. It has the advantage of being much easier to focus both at the transmitting and receiving end. The question is how to convert the sunlight into such a beam of light efficiently. Would you use LEDs, xenon lamps, lasers? How about just mirrors? It makes it far more efficient and also does away with the solar panels and the huge microwave antenna on the satellite replacing these with a set of mirrors. Also since light can be focused to a much smaller spot than microwave you could have a much smaller receiving station receiving a highly concentrated beam of light instead of microwaves dispersed over a hundred or so square kilometers. There are of course two big disadvantages. One is that it will be obstructed by clouds just as sunlight is, because it is indeed sunlight. The second is that if it were to go astray it would incinerate anything in its path. FInally it would be a huge source of light pollution with the area around it being brightly lit 24x7 by the light diffusing in the atmosphere especially when there is mist or clouds. Probably something that makes much more sense is to have solar thermal power plants with salt storage down here on earth in areas of the globe where sunlight is plentiful and invest in low loss DC transmission. Technically for Europe these would best be in places in the desert, perhaps in Morocco, but that may be unacceptable from a political/energy security point of view in which case a better but much more costly choice would be the ocean. In any case the cost for a given capacity would be far less than a space based system. Even the cost of a huge floating platform and the thousands of kilometers long DC submarine cables would pale in comparison to the cost of launching thousands of tons into space and building antennas measured in hundreds of square kilometers.

[@treborg777]

You & they neglect the fact that geostationary orbit is already crowded with satellites, both active and decommissioned. The solar power satellites will have to double as comm satellites for there to be room.

[@ignaciomoreno9655]

Sim City 2000 had this as one of the possible energy sources for the city. And the misdirection of the laser carrying the energy as one of the possible disasters.

[@bobbyshaftoe45]

Breakthroughs in solidstate maser tech [ironically, in Britain] have been made which seem ideal for high efficiency transmission. As a key element, it would be interesting to get your take on it.

[@meesalikeu]

and we would like to get your links for proof of breakthroughs nigel.

[@pewterhacker]

Really good video! I loved that you uncovered the report's use of "evidence by citation". The other thing that is worth mentioning is that the proponents of the technology claim that, thanks to Starship, launch costs to LEO will come down by a factor of 800 from the price-per-kg that NASA will pay SpaceX for the next five missions to resupply and crew-rotate the ISS. If that were likely to happen, wouldn't we have heard of, for example, plans by NASA to host its next agency-wide holiday party on the ISS?

[@HowardS185]

How much power would be generated by ordinary terrestrial solar panels covering the same area as the proposed microwave receiver?

[@Jesus.the.Christ]

The power can be beamed down to farmland. The rectennas can be placed over fields and don't have to block sunlight (the rectenna is not a wall, it's more like a fence). The rectenna stops the microwaves by absorbing them so they don't reach the ground. So where you place the rectenna is not a problem, farmers just need to accept that they've got a new revenue stream.

[@nos9784]

Also, we can finally discourage _all_ lifeforms from wandering into those fields! Seriously though, I hope this works out sooner or later.

[@danilooliveira6580]

@@nos9784 as she mentioned, the energy reaching the ground is 10x weaker than sunlight, and only in the form of non-ionizing radiation.

[@renatocorreaarrieche]

Only for farming in outer solar system

[@alihenderson5910]

Isn't a rectenna the place where the sun never shines?

[@nos9784]

@@danilooliveira6580 that may be true, but so far, it's in early developement, if it is that far. It's certainly too early to rule out lazy unscientific jokes. 😉

[@ericvosselmans5657]

Our current rocket and engineering technology is already advanced enough to build advanced space habitation for perhaps hundreds (or even 1000's) of people at the same time. Therefor: Building giant space-based solar power arrays is a very good idea (until nuclear fusion, or other hydrogen-related fuels), but use the power for stuff in space. To ultimately safe the planet from the disaster that is humanity, going to space en masse is a good idea I believe. I don't believe we will make manned interstellar travel work, but our solar system is a big enough place.

[@sarran1955]

Hello Sabine, Being an older Sci-fi fan, I would draw your attention to the 'young adult' book : Starman Jones by Robert Heinlein (1953), where our hero Max escapes as a young farm boy from a dismal future on an 'antenna farm', collecting the micro wave energy beamed from platforms in space.... Cordialement,

[@charlespentrose7834]

I guess I'll file this idea under "Cool sounding, but impractical without significant advances"

[@alihenderson5910]

I filed it under 'yet another funding grift'.

[@rainer9825]

Space based solar to replace power plants is hilariously inneficient, if it works at all. There could be a market in 20 years for smaller systems in LEO/MEO for security or mobility applications. But there are many technical challenges ahead.

[@ryanbrown982]

3:12 I like angry, indignant Sabine. We should get more of that.

[@laura-ann.0726]

Another issue not mentioned by Sabine: "parking slots" in Geostationary orbits are in limited supply, and a solar power array is HUGE, compared to a TV or telecommunication satellite. Plus, if some component failed in the solar array or the microwave transmitter, it would be very difficult and expensive to repair or replace. My gut feeling is that our technology isn't ready yet, to deploy a space-based system of this complexity. Nuclear power isn't a perfect solution either, but we do know how to build a 1200 megawatt CANDU reactor, that can burn unenriched uranium, recycled MOX fuel, or even Thorium 232, of which there is enough to run several hundred 1200 MWE reactors for several centuries. The CANDU is a well-established and reliable technology, and the cost per megawatt-hour for these power plants is also well-established. Electricity from Nuclear is not as cheap as coal or natural gas, but it doesn't dump thousands of tons of CO2 into the atmosphere every day, either, so there's a benefit there. I'd say that both Space-based solar and Fusion are eventually going to roll-out and take their places to provide electric power in the future, maybe by mid-century? but we are not there yet.

[@MrSupermeisi]

Maybe a video on how realistic a Dyson sphere is would be nice

[@simongross3122]

Ringworld would be more feasible. But probably still not feasible.

[@greebj]

cost per ton of shooting stuff up into space

[@Stringsmith]

any civilization with the resources, engineering, technology, and infrastructure to build a Dyson sphere would not need a Dyson sphere.

[@simongross3122]

@@Stringsmith Exactly. It would be a folly.

[@JFrazer4303]

Not at all feasible. Dyson never wrote about the bad S.F. idea of a contiguous or solid sphere, and he disliked his name being associated with it. What he wrote about were closer to O'Neill/Kalpana space colonies being built. Eventually a species without magic S.F. stuff like artificial gravity or continuous contained small-scale fusion or FTL will build enough colonies or solar power collectors that from the outside, the star looks like it's surrounded by a "shell" of stuff. In biology or astronomy, a "shell" is just a cloud of particles or stuff gathered around a central point. Not a solid sphere. He suggested a SETI search for stars embedded in a cloud of dark stuff that blocks sunlight but emits heat in the IR in the temperature of liquid water, as space colonies would. (a recent search of several thousand star clusters and galaxies that fit the "warm dark IR cloud of stuff" description, out a billion or so light years, found zero with suspicious EM noise/signals). He said that in the future as we expand at sub-light speeds out across interstellar space (eating comets to build space colonies accessible by ships that are too slow for rapid interstellar travel but entirely accessible between/among themselves) to other stars and colonize them, over thousands or tens of k years, those star systems would also begin to look like a dark, warm cloud of stuff is blocking sunlight and replacing it with warm IR and EM traffic. Over the eons, the stars in the sky are dimmed by their own Kardashev=2 civilizations each sending out "daughter" colonies. A "stain" of warm dimmed stars, spreading across the sky as life spreads across this galactic arm. He wrote that while it isn't actually a "green" cloud surrounding the stars, it does represent water and hence life, so he coined the phrase "the Greening of the Galaxy". A far grander vision (and involving no fantasy S.F. 'tech), than the bad S.F. fantasy sphere.

[@w0ttheh3ll]

Some significant technical challenges ahead, but I assume less difficult than fusion. In the end the feasibility comes down to launch cost.

[@Llortnerof]

It's basically nothing we couldn't already do. So the challenges are more in the lack of experience than lack of technical capabilities. We have all necessary parts, we just never tried putting them together like that.

[@monnoo8221]

Another typical stupid response by a brain-washed engineer. Ever heard about opportunity costs? using 16 bln right now for primitive solar tech provides you at least 2000 GWh per year....

[@tomaszdrgas8811]

thank You for talking about Brilliant on the end.. sorry for not watching your videos to the very end

[@theharper1]

I remember reading about this when I was growing up during the space race. Even then, it seemed like it could only work if the satellite was in geostationary orbit. Trying to transmit to a ground station from LEO would only work in short bursts, be hard to aim, and defeats the purpose to a large degree. But that means you need to get thousands of tonnes on payload to geostationary orbit, which is much more expensive than LEO. I'd like to know if there's any risk of heating the atmosphere, despite the proposed frequency making the atmosphere "transparent". The ground under the receiving rectenna could still be used for farming, although you'd need to convince people that animals living under the rectennna wouldn't be harmed. The more important point is to ask; if you spend the same amount of money installing solar panels on rooftops, wouldn't it be more efficient and easier to maintain?

[@Citizen_J]

Here I was thinking the sun was out in space and was beaming solar power at us the entire time

[@Argoon1981]

That is certainly true but we lose much more efficiency by capturing it down here, at lest using solar panels, the atmosphere and clouds interfere and of course the Earth rotates and we have night to kill the joy. But there's others indirect ways to harness its power, like wind and hydro for example they are also solar powered.

[@D0rus]

I find the pro of no carbon dioxide emission quite wild. Is this including carbon dioxide free space launches?

[@Argoon1981]

Some space agencies use methane for their rockets, because is more cost effective, but you can certainly have rockets that work only on hydrogen and oxygen and those make zero co2 as a byproduct, only water vapor, so yes ESA or NASA or others could decide for hydrogen but that is certainly not the cheap option and its byproduct, water vapor, may surprise some, has a strong greenhouse effect as well, so there's no "clean" way to launch rockets into space, the only way for that to happen, would be to totally stop launching rockets, stop working in outer space, never get off the ground and return to the dark ages and I doubt that will ever happen.

[@eddydogleg]

If they use a hydrogen generated from solar as the fuel for the rocket then is it will be a CO2 free space launch.

[@ianbrown1474]

How about a video on space elevators/tethers? I always thought Solar space generators would end up “hand-in-glove” with solving the problem of space elevators (tethers). If you can move materials and spares cheaply into space without the high risk and cost of rocket launch and then you can transmit the captured power back down the tether using it as a wire you seem to have most of the benefits with far fewer of the disadvantages: less land required for arrays, avoiding as much lossy transmission though obviously all the impossibly huge risks/challenges of tethers..might be a fun video ….

[@shawnlund]

Sabine, your dry humour is fantastic. Keep it up. 🙂

[@ixiairisborne1695]

I would invest in it. The thing I want to know is if the losses from beaming the energy down are less than the losses of ground-based solar cells.

[@von_nobody]

Question, how much energy we could use from rocket fuel that would be used to lift this solar panels?

[@dermaniac5205]

I did a quick google research and the answer seems it's not that much. A single launch uses about 6GWh of energy and a theorized satellite power plant would produce 2GW. That means for each launch required to assemble the plant, the plant only needs to run for 20 minutes longer in order to make up for the energy "wasted" in the assembly. I don't know how many launches it takes to assemble the plant, but even if you need 100 launches the plant paid for itself in one and a half days of operation.

[@benjaminfranklin329]

If we're including all the energy that would go into making rockets, and making the fuel, it would be a lot higher than the pure fuel energy... It's still probably not the biggest consideration, the economics are completely unsound

[@hoon_sol]

@@benjaminfranklin329: You were just confronted with calculations indicating that the economics can easily be sound.

[@sicadesign6078]

@@dermaniac5205 I've estimated an energy payback time of 23 days for the electrolysis and liquefaction of hydrogen propellent for a future, fully reusable LOX/LH2 launch vehicle (Skylon + upper stage) to place a 2 GW, 2000 tonne CASSIOPeiA into GEO. (Ian Cash)

[@benjaminfranklin329]

@@hoon_sol no, the fuel is very much not the biggest cost in launching rockets. Back of the envelope it's somewhere around USD3,000 per KG to Low Earth Orbit. So 5,000 tonnes would be ~USD15B. That doesn't cover the cost of the absolutely enormous ground antenna, the losses in transmitting via microwaves, the solar panels rated for Low Earth orbit, a realistic 15-20 year replacement lifetime, the maintenance of the solar array and the enormous ground antenna and the likely fires caused by it. No the economics have even vaguely been shown to be close to the most expensive ground based nuclear or renewable with storage system.

[@ericslavich4297]

I'm curious about the potential planet warming/cooling effects - Part of the time the space array is shading the planet, serving to cool it. But when the array is not shading the planet, we're taking sunlight that had been destined to pass by without hitting Earth and beaming some of that energy to the surface, warming the planet.

[@yasheng]

Nuclear plants warm up the planet anyway right?

[@vultureTX001]

maths - it's 36KM up and at Gsynch so no perceived shadow.. even 100KM2 ground station is one/ five millionth of surface.

[@ericslavich4297]

@Cancer McAids FIrst, nice name. Second, let's see. I was thinking more in terms of species-wide adoption of the technology, not the impact of a single array. If we redirect 10Tw of sun power to the planet (roughly total worldwide electrical generating capacity) that would amount to an increase of 1/10,000th in the total sun to Earth power. Okay, it's small. (Numbers based on quick internet search and may be wrong.)

[@morgan0]

the point where i decided it wasn’t worth it was when you said it would produce as much as a nuclear plant. when it can produce 10 times as much power and uses a frequency that would not cause damage if it missed the receiver, then it’ll be worth it.

[@laiag4854]

I almost see it easier to make the clouds move out of the spot where you have the solar panels somehow... Or even having the solar panels on a desert and transporting the electricity

[@martinknapp7640]

I noticed that you didn't say anything about the side-effects (if any) of sending a permanent high-powered microwave beam through the atmosphere. Are there any problems with that?

[@Dr.JustIsWrong]

Cooked birds? Hot showers outside? Wifi fires?

[@forbidden-cyrillic-handle]

​@@Dr.JustIsWrong You better stay safe in your Faraday cage.

[@klericer]

She said that 2-5GHz is "almost invisible" to the atmosphere. Hence, there would be very little interaction. I do not know if there would be any long-term impact but also the atmosphere is not a static block your the beam eventually "burns through".

[@Lund.J]

There is one advantage: People don't need to buy microwave ovens any more. You just hold the plate out the window and let the maser beam do the work.

[@martinknapp7640]

@@klericer It's the 'almost' that gets me. Small impacts can get bigger if they are prolonged enough or energetic enough, I have a nasty suspicion

[@tachikomakusanagi3744]

This is one of those bad ideas that just never goes away

[@arthurthomasware5004]

When I was a kid in England in the 1940's, a childrens' comic book came out with a story called, The Black Beam. It was, of course, science fiction. The idea was that space ships could be placed into the Black Beam thereby overcoming the pull of the earth's gravity and easily launched into space. Am wondering if such a thing will ever come to pass.

[@flagmichael]

I first heard about the idea of beaming solar power down from space in 1967, about the time I got my Novice amateur radio license. My first thought was "what happens if the power does not go where it should?" Those were the days of the first Apollo flights, when all these ideas were speculative anyway. Now I am retired and still wondering, "what about the side lobes?" Directionality for radio is accomplished by controlling propagation; that inescapably creates side lobes. For communications that is a nuisance, for power delivery it is something else. The good news: engineers can accurately predict side lobes and deal with them. The bad news is it can get complex. Here's hoping that is part of the design phase rather than a remediation phase.