Two Korean research institutes are designing a space solar power satellite project with the aim of providing approximately 1000 TWh of electricity to the Earth per year. The 95 gigawatts of nuclear in the US generates 800 terawatt hours per year. Spaced based solar at 120 gigawatts would generate 1000 terawatt hours.
This is an improved proposed Korean Space Solar Power Satellite (K-SSPS) project. It is a conceptual design of the satellite, its end-of-life disposal method, and a first pilot system and experiment.
The proposed system would use 4,000 sub-solar arrays measuring 10 meters × 270 meters and comprising thin film roll-out, with a system power efficiency of 13.5%.
It is not derived from rigorous analyses but rather serves as system requirements for commercial viability.
The system will have a mass of 10,000 tons per 2 gigawatt module and transmit microwave at a frequency of 5.8 GHz to Earth via a 1.0 square kilometer antenna. The microwaves can be converted on the ground to usable electricity via rectennas, which are special receiving antennas that are used for converting electromagnetic energy into direct current (DC).
On the ground, the researchers propose to place 60 rectennas with a diameter of 4 km along the Korean Demilitarized Zone (DMZ). In that case, 60 satellites will have to correspond to the 60 rectennas. If each rectenna could generate 2 GW, the total power collected would be 120 GW.
A successful SSPS could provide electricity at a price of 3 cents/kWh, significantly lower than that of nuclear power. This estimate is based on a scenario where the SSPS generates 2 GW of power, has a mass of 9192 tons, an installation cost of $11.4 billion (with a launch cost of $600/kg), and a 30-year lifetime. The full 120 GW system would be about 600,000 tons.
South Korea’s electricity consumption in 2022 was 548 TWh. This is why I know the statement about 1 TWh was wrong as they said this system would generate more energy than South Korea makes now.
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The idea of huge orbital solar cells goes back at least to the 1970’s. I saw an article in National Geographic I believe was from July, 1976. (I tried to confirm the date on the N.G. website, but it didn’t go back that far. My God, that was the last century!) It talked about mining the moon to provide materials for orbital solar platforms in Earth orbit. This idea makes a hell of a lot of sense. I supposed I’m not surprised, a small country, w/limited geography and resources is seriously looking at this. And you don’t have to mine the moon to begin this, but that’s a logical next step…
All of space flight has put roughly 16k tons into space. Over 70 years.
And they want to put 600k tons into space for their setup? That’d be 4000 dedicated Starship launches.
So I’m guessing someone missed on their math here that this would be cheaper.
“I drink your sun-ray milkshake!” – Anon Energy Farmer
If microwave mirrors were placed in space, seasonal solar power variability could be mitigated by beaming up excessive energy generated from solar farms in the southern hemisphere during its sunny summer to the sun-starved northern hemisphere which is simultaenously in Winter.
This is why I support nuclear power. SSP will make Starlink look like a minor inconvenience. The one good thing about this is that it’s in GEO which the light pollution is always on the other side of the planet…for now.
This one is 6,8 km but 36000 km up, so the angle in the sky is 19 mRad
Starlink is about 10 meters and 550 km up, so 1,8mRad
It would compare better to ISS, 109 meters, 400 km up, so 27 mRad.
So smaller than ISS, and not moving, I dont think its a big deal.
Also 400 of these could power all humanity in 21000 with no fossil fuel.
Would this not heat any water in the atmosphere and therefore add to global warming?
If the beam is in a frequency that can be absorbed by water molecules, then it is a danger to people who are made of 75% water. So, not only it’s a good idea to use frequencies that aren’t absorbed by water b/c of global warming and losing some of that energy to ambient moisture, it’s also a good idea to not microwave people to death.
By siting this with the microwave download to fields along the DMZ, then this might be as much a defense installation as it is a power project. For defense purposes, microwaving people to death is a feature.
Alternately it might be driven by the availability of open & undeveloped land in South Korea. They kind of have a lot of people living on that small peninsula.
Would this not heat up any moisture in the atmosphere and therefore speed up global warming?
Seems like it would be a lot easier and cheaper and compact to build 4th gen nuclear power on the ground.
Just aim in a few yards north and you can start taking out guard towers.
I’ve always wondered what would happen if the beam misses the rectenna and hits, I don’t know, a population center.
As normally planned, you have two features that are protective:
1) The antenna size is chosen so that it’s physically impossible for the beam to be focused to destructive intensity. The maximum intensity you can reach is theoretically too low to cause acute harm.
2) The focus is maintained by using a ground based phase reference, which results in the beam defocusing if the reference is shut off.
Now, in theory you could apply a calculated offset to the phase reference to shift the target point away from the rectenna, but there’s no way to circumvent the beam size short of building a larger antenna, which everyone can see you do.
If we want clean energy the only way to go is closed loop geothermal. Have a look at the work these guys are doing:
https://www.youtube.com/@Eavor
This should really be a Manhattan type project to have this established ASAP.
And what do we who live away from geological faults do? Go without? No, nukes are the way to go, if space solar is off the table.
Bold, I’ll give them that. But first you would want a MUCH smaller setup, and have the demo run at least a few years, to see how well the solar panels hold up, is the efficiency degraded, any antenna issues, etc, plenty of bugs to get ironed out.
Honestly, by the time you work out the kinks, fusion will probably exist, making the whole thing pointless, cause I expect nuclear fusion reactors to make nearly all other forms of creating electricity, obsolete.
I like your “gung ho!” enthusiasm, Murc. However, I do NOT think such a thing in space would be invalidated by (one hopes…) cheap, ubiquitous fusion power.
Because at least as it is being researched today, fusion-based power doesn’t hold much promise of being EITHER cheap or ubiquitous.
The ‘thing’ that made old-fashioned fission power so easily embraced was this … from a technology point of view, one needs merely to put a big enough pile of enriched fission fuel in one place, and all by itself, it spontaneously starts to fizz and make a LOT of heat. In fact, special rods of another material need to be inserted inside the pile to keep the whole thing from running away and melting down.
Piles … of anything … aren’t very high tech. they’re piles.
By comparison, fusion based power schemes come in essentially 3 flavors. [1] Magnetically confined super-hot gasses, [2] little exquisitely machined containers of gold, and fast-moving beams shaped and directed to slam into each other.
[1] has the annoying problem of the gas being incredibly unwilling to ‘stay in the bottle’, no matter how exquisitely it is crafted by the scientists and engineers. Unlike “the pile” idea, which just requires a bigger pile to make more energy, but no exotics, the bigger bottle idea (so far at least) hasn’t scaled as hoped. Oh, ITER and the other big donut machines are promising, but power making? Nah. After what, 60 years?
[2] requires astoundingly large and esquisitely timed lasers to create ultra-short beams of energy and simultaneously hit the little pea-sized targets at exactly the same time. Which causes an avalanche of X-Rays to illuminate and evaporate the surface of a lil’ bead-of-a-target, compressing its interior enough to cause fusion to happen.
The only problem is, that the resulting blast almost nearly destroys the container holding it. Ah… er… not so good for cheap-ubiquitous power. And of course the scale of the machines. Many buildings worth of lasers.
And still no power.
[3] Has long been promising, but researchers early on also determined tha the energy-cost of making the colliding beams pretty much was on the same order as any hoped-for energy production. So… 10 watts in, to get maybe 1 to 100 watts out. At the 100 end, its attractive. At the 1 end, its a loss.
And nowhere near as simple as a BIGGER PILE in fission’s case.
So, that is why “cheap ubiquitous” fusion power is almost certainly not going to happen anytime soon. Indeed — for the last 50 years, I’ve been wondering if ANY advance will somehow revolutionize it to achieve just the “cheap” side, let alone “ubiquitous”.
⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
⋅-=≡ GoatGuy ✓ ≡=-⋅
Their 3c/kWh cost estimate is based on $600/kg to LEO.
I’ll take the under.
Well, it “kind of foots”. (the numbers)
Just from the pretty picture at the top, one can see that there are 20 of the 500 meter by 1000 meter panels or a total of 10,000,000 m² more or less of panel area per satellite. Given stated 13.7% efficiency and 1360 w/m² of raw energy in space, that corresponds to about 1,900 MW of generation or so. Probably more like 2,000 MW if I use their specific numbers. Same ballpark.
So, 120 GW would be 60 of these things? Wow. That’s pretty adventurous. Remarkably so. Geosynchronous orbit is what, 35,000 km up? The wavelength of 5.4 GHz microwaves is … mmm… 5.6 cm. Remembering the Raleigh’s diffraction limit equation (which wäve-physics simply cannot do better than for physical reasons), of [α = 1.22λ/D] where α is angular resolution, λ is wavelength in meters, and D is diameter of the transmitter/receiver in meters …
1.22 × 5.56×10⁻² m ÷ 1000 m = 67 μ-radians.
Multiply by the baseline (35,000,000 m), to get 2,370 m ‘spot size’. On planet Dirt, from a 1 km transmitter ‘up there’.
Hmmm… quite a bit larger than the proposal. Are they really planning on GEO orbit? Closer orbit has a problem — the durn satellites move about the ground stations don’t. Moreover, you need to build a LOT more of them to get good 24-hour-a-day coverage. I guess there’s the angle of selling megawatt-hours to anybody with a bag of money (and willingness to install a far smaller ground station, given the much-closer orbit). Hey, international power brokering.
As far as my napkin math works out, either the combination of GHz (needing to increase), the size of the transmitting array needs increasing, and only then can smaller ground stations be Physics reasonable.
Dunno. I think building nuclear power plants still makes a LOT more sense. Especially if they are designed around using a combination of thorium and “useless-for-bombs” pickled plutonium. Y’know?
Much fewer issues with the Norks targeting them either. Or passing hailstorms. Tornadoes. Typhoons. Those ground-based rectennae are … sensitive to that shît.
⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
⋅-=≡ GoatGuy ✓ ≡=-⋅
You’re the schnizz, GG. Do you have your own blog or channel? Plus you think in metric and not imperial, which is always a bonus.
Weapon potential?
We know that solarpanels om earth degrade in performance when getting to hot, have the factored that into consideration ?
Also Maintenance and Ownershipcosts, How well do these panels stack up against long exposure to cosmic rays ?
So, they’re planning to put all the critical ground infrastructure within easy mortar range of North Korea? Seems imprudent.
For N. Korea to attack ANY target in S, Korea means war. It’s not imprudent for South Korea to place infrastructure w/in their territory were ever it’s logical to do so. If N. Korea is so stupid to attack anything in S. Korea, well, that’s very stupid.
A 30 year productive lifetime for roll out solar film? With that level of radiation? If they can do it, more power to them. I just didn’t realize that type of panel was that durable under the extreme radiation of space. Are these type of solar cells currently in use on some satellite? Maybe they should consider sending up a very small patch of their plasticized solar panels first. Just for some realistic durability testing before spending 11 billion. I know they have vacuum chambers and strong lights in labs, but they can only run test for so long and extrapolate so much. I’m just have a tough time with that 30 years of operation projection. Lastly how can they beam down power from GEO without regularly energizing/interfering with antennas and panels from Elons’ or Bezos’ LEO satellite clusters? Who runs the FCC for space?
Just what we need, another 1000 TWh of power turned into waste heat in our atmosphere.
Oh noes 1000 TWhr over a whole year? How ever will that compare to the 5,455,728,000,000 TWhr that the Sun gives the Earth every year?
Quick! To your fainting couch!
Other data suggests 5 to over 30% of global warming is caused by waste heat, such as HVAC systems, on top of the greenhouse gas effect. Why add to that? Anyhow, with that much solar, why play with big space toys? Time for you to get off the couch!
“5%-30%”
Quite the error bars there.
“Why play with big space toys” I’m sensing some toy envy but you put the panels in space so that they get daylight 24 hours a day and can provide baseload power, something solar pannels cannot do on the ground.
You seem to be thinking about the ‘urban heat island’ phenomena. If it reaches 50C in the streets of Manila Philippines, it’s not the same thing as a ‘record high’. Instead that’s poor circulation.
Environmentalists: Solar is what we need!
Me: Ok how about solar powered space satellites?
Environmentalists: Not that solar!
Yup. May interfere with potential tardigrade migration amongst the stars!
The issue with space based solar from the standpoint of global warming is that de facto it is increasing the amout of solar radiation that hits earth: you capture more radiation in space and beam it to earth were will still produce heat so you end up heating the planet more. However I do not think it is truly feasible because i do not see the discussion about heat dissipation for the panels in space: it is very difficult to cool stuff always floating in direct sunlight, sure it will heat up until you get an equilibrium between the heating and the radiative cooling, but i am not sure the thin film panels will work without a good radiative array (that will greatly increase the mass of the structure)
“The issue with space based solar from the standpoint of global warming is that de facto it is increasing the amout of solar radiation that hits earth”
If you care so much then compare the waste heat added to the Earth for SSP to the waste heat added to Earth for a combined cycle gas plant that dumps 2GWth in to the air.
Otherwise you just hate energy and are making our future AI overlords angry.
Mass and volume (size) are two different things. Solar panels (composed of a number of different materials these days, not just straight silicon) in space are, we’ve discovered surprisingly robust. Your right to consider thermal expansion/contraction on the “frame” containing the solar cells. But that can be dealt w/by designing the frame w/the materials, and physical design to do just that: Expand and contract.
Second, “beaming” energy to Earth, is not the same as imparting thermal energy to Earth. Using microwave or laser frequencies does not send thermal frequency heat to Earth’s surface.
(One of the interesting “deficits” of solar cells, historically is they can’t harvest lower frequency light; ie: the infrared. We now know how to directly convert thermal energy into electricity. A “solar cell” that did this, along w/what they traditionally do, harvest near&UV frequencies, would be quite interesting…) Oh well…
Oh yes let’s start worrying about thermal pollution now…. /s
6kwh/m2 average insolation…
I mean sure the Sun toasts the whole earth every day but trust me that extra bit of waste heat is going to do us in.
From the article:
“Per the proposal, the satellite bus will first get into the Low Earth Orbit (LEO), where the main structure and the solar arrays will be installed. After conducting some tests, harvested energy will power the K-SSPS journey from the LEO to the geostationary orbit (GEO).”