Summarizer

That's even more reason that if we manage to increase the amount of solar energy cells by 1000x there are so many more effective ways to use it than immediately flinging them into space. They're not getting constructed as satellites mid-orbit, after all.

The problem Elon is trying to address is a societal one, not a technical one. The amount of push back on clean energy generation and manufacturing prevents data centers on earth from being as feasible as they should be. He only got his newly opened xAI data center open using temporary generators on trailers and skirting the permitting process by using laws designed for things like traveling circuses.

> doesn't seem likely to have many broader implications on its own Considering how foundational energy is to our modern economy, energy several orders of magnitude cheaper seems quite likely to have massive implications. Yes it might be intermittent, but I'm quite confident that somebody will figure out how to effectively convert intermittent energy costing millicents into useful products and services. If nothing else, incredibly cheap intermittent energy can be cheaply converted to non-intermittent energy inefficiently, or to produce the enablers for that.

They worked out because there was an excess of energy and water to handle it. We will see how the maths works out given there is 19 GW shortage of power. 7 year lead time for Siemens power turbines, 3-5 years for transformers. Raw commodities are shooting up, not enough education to cover nuclear and SMEs and the RoI is already underwater.

My cynical take is that it'll works out just fine for the data centers, but the neighbouring communities won't care for the constant rolling blackouts.

Okay but even in that case the hardware suffers significant under utilisation which massively hits RoI. (I think I read they only achieve 30% utilisation in this scenario)

Why would that be the case if we assuming the grid prioritizes the data centers?

Is that more or less absurd than making deals with our neighbours to share their electricity? Build some solar farms around the planet and then distribute it over wire. I honestly don't know the answer. I know there's some efficiency loss running over long wires too but I don't know what's more realistic.

In theory you can do HVDC over long distances. In practice that doesn't help much. Power would normally want to run north to south (not gonna do HVDC across the oceans anytime soon), and so the terminator hits you at the same time everywhere. It's got to be batteries if you want PV at scale. The practical difficulties aren't really long distance transmission though. They're political and engineering. Spain had a massive blackout recently because a PV farm in the south west developed a timing glitch and they couldn't control the grid frequency - that nearly took out all of Europe and the power wasn't even being transmitted long distance! The level of trust you need to build a giant integrated continent-wide power grid is off the charts and it's not clear it's sustainable over the long run. E.g. the EU threatened to cut Britain's electricity supplies during Brexit as a negotiating tactic and that wasn't even war.

HVDC would be a lot less connected than an AC grid. The real question is, why do you expect Space to have fewer political and engineering issues.

I concur it’s not necessarily totally absurd — but when you consider that such contraptions require large — very large! — receiving arrays to be built on the ground, it’s hard to avoid concluding that building gigantic photovoltaic arrays in, say Arizona (for the US) along with batteries for overnight buffering and transmission lines would still be massively more efficient.

> it would be advantageous to have a bunch of smaller satellites, if you were concerned about cooling them. ...That's only relevant if you start from the position that your datacenters have to be space. You could already make smaller datacenters on earth, and still have better cooling, if you were concerned about that. We don't do that because on earth it's more efficient to have one large datacenter than many small ones.

If we (as in "civilization") were able to produce that many solar panels, we should cover all the deserts with them. It will also shift the local climate balance towards a more habitable ecosystem, enabling first vegetation and then slowly growing the rest of the food chain.

> It will also shift the local climate balance towards a more habitable ecosystem, enabling first vegetation and then slowly growing the rest of the food chain. Depends on the deserts in question and knock-on effects: Saharan Dust Feeds Amazon’s Plants. * https://www.nasa.gov/centers-and-facilities/goddard/nasa-sat... Helping vegetation in one place to grow may hinder it somewhere else. How important this is still appears to be an open question: * https://www.nature.com/articles/s43247-020-00071-w I'm not sure if humans are wise enough yet to try 'geo-hacking' (we're already messing things up: see carbon dumping).

I don't think it's insane. It might not work or be competitive but it's not obviously insane. In a frictionless economy governed by spherical cows it'd be insane. But back here on Earth, AI is heavily bottlenecked by the refusal or inability of the supply chain to scale up. They think AI firms are in a bubble and will collapse, so don't want to be bag holders. A very sane concern indeed. But it does mean that inferencing (the bit that makes money) is constantly saturated even with the industry straining every sinew to build out capacity. One bottleneck is TSMC. Not much that can be done about that. The other is the grid. Grid equipment manufacturers and CCGT makers like Siemens aren't spinning up extra manufacturing capacity, again because they fear being bag holders when Altman runs out of cash. Then you have massive interconnection backlogs, environmentalists attacking you and other practical problems. Is it easier to get access to stable electricity supplies in space? It's not inconceivable. At the very least, in space Elon controls the full stack with nearly no regulations getting in the way after launch - it's a pure engineering problem of the sort SpaceX are good at. If he needs more power he can just build it, he doesn't have to try and convince some local government utility to scale up or give him air permits to run generators. In space, nobody can hear you(r GPUs) scream.

Building nuclear-powered and solar powered datacenters in places with low population density will still be cheaper. Do you think Mongolian government won't allow China to build datacenters if the price is right?

It might be easier in China but that doesn't help Elon or Americans. Solar powered datacenters on Earth don't make sense to me. The GPUs are so expensive you want to run them 24/7 and power cycling them stresses the components a lot so increases failure rate. Once it boots up you need to keep the datacenter powered, you can't shut it down at night. Maybe for CPU datacenters solar power can make sense sometimes, but not for AI at the moment. Nuclear is super hard and expensive to build. It probably really is easier to put servers in space than build nuclear.

It's about creating a flywheel for scale. Getting better at creating and erecting solar panels & AI datacenters on earth is all well and good, but it doesn't advance SpaceX or humanity very much. At lot of the bottlenecks there are around moving physical mass and paperwork. Whereas combining SpaceX & xAI together means the margins for AI are used to force the economies of scale which drives the manufacturing efficiencies needed to drive down launch etc. Which opens up new markets like Mars etc. It is also pushing their competitive advantage. It leaves a massive moat which makes it very hard for competitors. If xAI ends up with a lower cost of capital (big if - like Amazon this might take 20 years horizon to realize) but it would give them a massive moat to be vertically integrated. OpenAI and others would be priced out. If xAI wants to double AI capacity then it's a purely an automation of manufacturing problem which plays to Elons strengths (Tesla & automation). For anyone on earth doubling capacity means working with electricity restrictions, licensing, bureaucracy, etc. For example all turbines needed for electricity plants are sold years in advance. You can't get a new thermal plant built & online within 5 years even if you had infinite money as turbines are highly complex and just not available.

I can't see any reason to put them underwater rather than in a field somewhere. I think the space rationale is you may run out of fields.

> This is in reference to a vision the (distant?) future where the satellites are manufactured in factories on the Moon and sent into space with mass drivers. In the meantime, how about affordable insulin for everybody?

Isn't it already somewhat affordable? https://worldpopulationreview.com/country-rankings/cost-of-i... It's a political problem, not a tech problem

Why is it cheaper to ship all of the materials to space, then to the moon for assembly (which also includes shipping all of the people and supplies to keep them alive), then back into space vs just… building them on earth and then shipping them up? We’re not exactly at a loss for land over here.

> We currently make around 1 TW of photovoltaic cells per year, globally. Doubling every three years; at that rate it would take about 30 years for 1TW to become 1000TW. Whether on not the trend continues largely depends on demand, but as of right now humanity seems to have an insatiable demand for power.

I think it largely depends on what bottlenecks exist that we haven’t hit yet.

We’re not going to use 100% of our solar panel manufacturing capacity to power space data centers, specifically because everyone else on the ground is so power-hungry. If we’re being generous, it could maybe top out at 1%, which adds another ~20 years to your timeline for a total of 50. I think it’s safe to say this part is bunk (along with everything else about this plan which is also bunk).

We seem to be using 100% of our DRAM manufacturing for AI. So it's not completely out of the question.

Space to put them, terrestrially, is not infinite. Demand has a hard ceiling.

Plenty of space still, but we're running into other scaling issues now - power grids are at their limits. And on sunny days there's a lot more supply than demand, but that can be mitigated by adding more (battery) storage.

That's a supply ceiling. Funnily, it's also one that's solved by putting them in space.

It is more than 5x less expensive to get surface area on earth’s surface.

Yeah, soft costs like permitting and inspections are supposedly the main reason US residential solar costs $3/watt while Australian residential solar costs $1/watt. It was definitely the worst and least efficient part of our solar install, everything else was pretty straightforward. Also, running a pretty sizable array at our house, the seasonal variation is huge, and seasonal battery storage isn’t really a thing. Besides making PV much more consistent, the main thing this seems to avoid is just the red tape around developing at huge scale, and basically being totally sovereign, which seems like it might be more important as tensions around this stuff ramp up. There’s clearly a backlash brewing against terrestrial data centers driving up utility bills, at least on the East Coast of the US. The more I think about it, the more this seems like maybe not a terrible idea.

So far most of the datacenters are built in very convenient places and people will start to build them in inconvenient places like Sahara or Mongolia way before they will building them in space

Do you imagine there'd be less red tape involved in launching multiple rockets per day carrying heavy payloads? Like this argument just gets absurd: you're claiming building a data center on earth will be harder from a permitting perspective than FAA flight approval for multiple heavy lift rocket launch and landing cycles. Mining companies routinely open and close enormous surface area mines all over the world and manage permitting for that just fine. There's plenty of land no one will care if your build anything on, and being remote with maybe poor access roads is still going to be enormously cheaper then launching a state of the art heavy lift rocket which doesn't actually exist yet.

Ok, why are so many being built in Northern Virginia, rather than in the middle of nowhere where there will be no backlash? And permitting is challenging in part because it’s so different from place to place. Their permitting process with the FAA seems pretty streamlined.

> There's plenty of land no one will care if you build anything on I wonder if this is actually true.

Right now it is. However, the amount of available land is fixed and the demand for its use is growing. Solar isn't the only buyer in this real estate market.

We have so much excess land with no real use for it that our government actually pays farmers to grow corn on it to burn in cars. Availability of land for solar production isn't remotely a real problem in the near term.

This is really underselling it tbh. Any land that's growing corn in a developed country is likely top 1% of land on earth. Half of the earth is desert and tundra. Which is still incredibly easier to work with than space because you can ship there with a pickup very cheaply. Maybe when nevada and central australia are wall-to-wall solar panels we can check back on space.

The Technology Connections Youtube channel recently did a great video arguing pretty convincingly that the land used to grow corn for cars would be vastly more efficiently used from an energy perspective if we covered it with solar panels.

This. I feel like everyone just lost their mind.

You just have to remember, most of these people live in high density regions and have little comprehension about how much surface area humanity truly occupies... And that isn't even accounting for offshore constructs.

Realizing the impracticality of it (and that such approaches often collapse under the infeasibility of it) ... wouldn't it be better to... say... cover the Sahara in solar panels instead? That's gotta be cheaper than shipping them into space. https://inhabitat.com/worlds-largest-solar-project-sahara-de... https://www.theguardian.com/business/2009/nov/01/solar-power... (and a retrospective from 2023 - https://www.ecomena.org/desertec/ )

Solar can always just go on the roof...

Sure but like, just use even more solar panels? You can probably buy a lot of them for the cost of a satellite.

>just use even more solar panels I think it's because at this scale a significant limit becomes the global production capacity for solar cells, and SpaceX is in the business of cheaper satellites and launch.

“This scale” is not realistic in terms of demand or even capability. We may as well talk about mining Sagittarius A* for neutrons.

You don't even need a particularly large scale, it's efficient resource utilization. Humanity has a finite (and too small) capacity for building solar panels. AI requires lots of power already. So the question is, do you want AI to consume X (where X is a pretty big chunk of the pie), or five times X , from that total supply? Using less PV is great, but only if the total cost ends up cheaper than installing 5X the capacity as terrestrial PV farms, along with daily smoothing batteries. SpaceX is only skating to where they predict the cost puck will be.

You seem to be ignoring the substantial resource cost of putting them up there.

> it is possible to put 500 to 1000 TW/year of AI satellites into deep space, meaningfully ascend the Kardashev scale and harness a non-trivial percentage of the Sun’s power Which satellites are operating from "deep space"?

> We currently make around 1 TW of photovoltaic cells per year, globally. China made 1.8 TW of solar cells in 2025. The raw materials required to make these are incredibly abundant, we make as much as we need.

you realize the factor of 2 you introduce doesn't meaningfully change the order of magnitude that the previous poster is implying right?

You missed the point. We can make ten or hundred times the number of solar cells we make right now, we just don't have a reason to. The technology is fairly ancient unless you want to compete on efficiency, and the raw materials abundant.

>We can make ten or hundred times the number of solar cells we make right now Tomorrow? The limit isn't just about the current capacity or the maximum theoretical capacity, it's also about the maximum speed you can ramp.

>Tomorrow? Eventually :) Markets are forward looking, and not really bound to 'tomorrow'.

Do we really need to say (on HN especially) that time-to-market does matter? Not just for startups either. If you ramp up the Polio vaccine in 1 year vs 10 years, that has a big impact on human wellbeing. The two scenarios are not equivalent outcomes, even though it still happens "eventually." Speed matters.

Sure, speed matters. Developing new technology happens to matter more. I'm sure investors are going to do their own analysis on this and reach their own conclusions, you should try betting against it.

you would need 200 times the number of solar cells. I don't think you appreciate the scale that 200x is, especially when China is already: 1. quite good at making solar cells 2. quite motivated to increase their energy production via solar

The bottleneck is deploying solar physically, not making the cells. We have increased the manufacturing of pretty much every piece of technology you see in front you by 200x at some point in history. Often in a matter of years.

What do you think the limiting factor is? I don't see why we can't scale manufacturing of satellites up as far as we want. If we mine out a substantial fraction of the mass of the earth, we can go harvest asteroids or something.

>> Dyson Sphere > What do you think the limiting factor is? You need to be able to harness enough raw material and energy to build something that can surround the sun. That does not exist in the solar system and we do not yet have the means to travel further out to collect, move, and construct such an incredibly huge structure. It seems like a fantasy.

Great. Now run the numbers to find the energy required to disassemble the planets and accelerating the pieces to their desired locations. For reference, it takes over 10 times of propellant and oxidant mass to put something in LEO.

There are only so many people who can make satellites; there are only so many things to make satellites out of; and there are only so many orbits to put them in. There are only so many reasons why a person might want a satellite. There are only so many ways of placing satellites in orbit and each requires some amount of energy, and we have access to a finite amount of energy over time. Finally, if we limited ourselves to earth-based raw materials, we would eventually reach a point where the remaining mass of the earth would have less gravitational effect on the satellite fleet than the fleet itself, which would have deleterious effects on the satellite fleet. Seven reasons are intuitive; I’m sure there are many others.

People can build a factory that makes satellites. And then a factory that makes factories to make satellites. There is plenty of material in the solar system (see my other response), and plenty of orbits, and launch capability can scale with energy harvested so the launch rate can grow exponentially. Lots of people will probably decide they don't want any more satellites. But it only takes a few highly determined people to get it done anyway.

> Finally, if we limited ourselves to earth-based raw materials, we would eventually reach a point where the remaining mass of the earth would have less gravitational effect on the satellite fleet than the fleet itself, which would have deleterious effects on the satellite fleet. The Earth's crust has an average thickness of about 15-20 km. Practically we can only get at maybe the top 1-2 km, as drill bits start to fail the deeper you go. The Earth's radius is 6,371 km. So even if we could somehow dug up entire crust we can get to and flung it into orbit, that would barely be noticeable to anything in orbit.

Once you dig up the top kilometer of a planet's crust, what's under your feet? The next kilometer! That would suck to do to Earth, but we can launch all of Mars's mass into the swarm.

The physical amount of material in the solar system is a pretty big limiting factor.

Yeah, but besides not having the physical amount of material available in the solar system, or the availability of any technology to transfer power generated to a destination where it can serve a meaningful purpose in the foreseeable future, or having the political climate or capital necessary for even initiating such an effort, or not being able to do so without severely kneecapping the habitability of our planet, there are aren't really any meaningful barriers that I can see.

I wonder what the plan is to recycle those. Without a plan to safely bring back all this hardware and recycling it, we'll deplete earth from it's mineral. The matter used to build things on earth stays within earth's ecosystem. Moving matter out continusously at industrial scale with no plan to bring 100% of it back in the ecosystem other than burning it seems quite unsustainable and irresponsable.

Earth does have plenty of sand and iron. Literally all you have to do is grow the sand into a crystal, slice it up, etch some patterns onto it, then add some metal. Making only 1TW of pv cells per year is a skill issue.

Sure, and copper, and aluminium

Of course, we are stripping the earth bare to build word-guessers GPUs in orbit, but aliens are definitely the problem.

Considering we’re not actually “stripping the earth bare” and that’s fear mongering hysteria… I’d be interested to know the facts if true.

Help me understand something. We make 1 TW of cells per year but we're struggling with bringing 1 GW consuming data centers online?

It's much easier to find a country or jurisdiction that doesn't care about a bunch of data centers vs launching them into space. I don't get why we aren't building mixed use buildings, maybe the first floor can be retail and restaurants, the next two floors can be data centers, and then above that apartments.

I think data centers, in the areas where they are most relevant (cold climates), are going to face an uphill battle in the near future. Where I live, Norway, we've seen that: 1) The data centers don't generate the numbers of jobs they promise. Sure, during building phase, they do generate a lot of business, but during operations and maintenance phase, not so much. Typically these companies will promise hundreds of long-term jobs, while in reality that number is only a fraction. 2) They are extremely power hungry, to the point where households can expect to see their utility bill go up a non-trivial amount. That's for a single data center. In the colder climate areas where data centers are being promoted, power infrastructure might not be able to handle the centers (something seen in northern Norway, for example) at a larger scale, due to decades of stagnation. 3) The environmental effects have come more under scrutiny. And, unfortunately for the companies owning data centers, pretty much all cold-climate western countries have stringent environmental laws.

In Switzerland infomaniak built a data center under apartments and DC heat is used for heating. There are some videos about it.

The US has district heating systems. The country is very big and varied, as much as people like to paint it as homogenous.

And district cooling. When I lived on a chilling grid, my summer AC bill was around $80, while friends whose buildings weren't connected paid $200+.

Data centers don't do anything other than sit there and turn electricity into heat. They only emit nothing but heat (which could be useful to others in the building).

In America they have "temporary" jet turbines parked next to them burning gas inefficiently with limited oversight on pollution and noise because they are "temporary".

Heat and noise. The noise and the increased electrical bills are the main things people living near data centers complain about.

This is a classic case of listing all the problems but none of the benefits. If you had horses and someone told you they had a Tesla, you'd be complaining that a Tesla requires you to dig minerals where a horse can just be born!

It's a matter of deploying it for cheaper or with fewer downsides than what can be done on earth. Launching things to space is expensive even with reusable rockets, and a single server blade would need a lot of accompanying tech to power it, cool it, and connect to other satellites and earth. Right now only upsides an expensive satellite acting as a server node would be physical security and avoiding various local environmental laws and effects

> Right now only upsides ... You are missing some pretty important upsides. Lower latency is a major one. And not having to buy land and water to power/cool it. Both are fairly limited as far as resources go, and gets exponentially expensive with competition. The major downside is, of course, cost. In my opinion, this has never really stopped humans from building and scaling up things until the economies of scale work out. > connect to other satellites and earth If only there was a large number of satellites in low earth orbit and a company with expertise building these ;)

> And not having to buy land and water to power/cool it. It's interesting that you bring that up as a benfit. If waterless cooling (i.e. closed cooling system) works in space, wouldn't it work even better on Earth?