[jiggawatts]

Elon explained the logic at length in an interview: Cheaper != Available.

The availability of power is the constraint almost everywhere, no matter how much money you throw at it.

Gas turbine production has a many-year backlog. Everybody that can make the single-crystal superalloy turbine blades is fully booked for most of a decade and can't expand capacity for years (at least).

Meanwhile, putting a slightly larger solar panel onto a satellite is a trivial engineering excercise and has no blockers in 2026.

Disclaimer: Personally, I suspect all this AI-in-space "talk" from Elon is just cheap marketing to boost the IPO of xAI.

[dullcrisp]

Okay but why not take that slightly larger solar panel and leave it on Earth?

Is the sunlight millions of times brighter beyond the atmosphere? I don’t get it.

[ericd]

In space, that solar panel is always in the sunlight. No clouds, no night time. Weirdly enough, earth is a more challenging environment in some ways for solar. You need to lay out >3x the number of panels on earth to get the same power production, and you need batteries or a grid interconnection as a buffer.

Also, there's a populist backlash on building datacenters, power transmission infra, and power generation in many areas on earth. Locally, we have a number of people complaining about solar arrays going up on farmland, even though it's the farmers choosing to do it. "It's an eyesore".

[dingaling]

> In space, that solar panel is always in the sunlight

Only in a Sun-synchronous orbit, at specific elevations. Most 'normal' orbits have periods of shade.

[ericd]

Right, sorry, I meant in the orbits they're considering for these - I think they're mainly considering sun-sync.

[dullcrisp]

How big is it? I have some space I’m not using, no pun intended.

[ericd]

How big are panels? If you get 60 cell panels, about 68x45 inches/1.7m x 1.1m. Our home array is 60 of those, 24kw.

Example of a spec sheet: https://signaturesolar.imagerelay.com/share/ffc69ee2265b4613...

If you mean the farmers' arrays, those are meant for commercial generation, so a good bit bigger, but one nice thing about solar is it's extremely modular, and you can fit it to the land. I believe bigger panels are more common for commercial, but I think it's a lot nicer to handle 40-50 pound panels than 70 pound panels.

[dzhiurgis]

> Okay but why not take that slightly larger solar panel and leave it on Earth?

Because panel cap factor is about 10-20% to begin because day and night exists on earth. Say you wanted to power it on solar + batteries and picked Australia. You pick place that has decent port and most exposure, i.e. Port Hedland. In winter, daily average drops by 20%. Also because atmosphere - 30% less insolation when compared to space. Finally add 10-45% cooling losses.

Which effectively means you need something at least 10-20x more panels + batteries to match space.

[piloto_ciego]

You have to ask permission to build it somewhere. Nobody is going to stop you in space.

[troyvit]

What are the benefits of a solar panel in space vs a solar panel here on Earth? I get that there's less "night" up there, and there's less interference from the atmosphere so the solar is more efficient, but is it that much more efficient that it actually makes more sense than solar panels on earth?

[shaewest]

Admittedly asked Claude, but improvements are estimated to be x6-8 improvements on energy collection