[notahacker]

The unit economic tradeoffs aren't quite that straightforward (beamed power is lossy enough to require more panels[1], but solar cells and satellite structures have longer useful lives than inference chips so over longer time periods you likely end up launching more stuff into space with disposable datacentres anyway[2], particularly given the datacentres also need bigger radiators. Other issues which favour power being beamed to the ground are not exposing those expensive chips to radiation, and being able to replace them on cycles dictated by inference chip innovation or end-of-life rather than fixed cycles depending on a satellite propellant budget...

The other comparison point is of course plain old terrestrial power sources, including energy storage in the mix if it relies heavily on solar power without a sufficiently global grid. Not having to launch into space buys a lot of power.

C2 RTT times and edge computation of large datasets collected in space make much more sense since unit economics aren't the driving factor, but are unlikely to need datacentres on the same scale as inference compute for the general population (another reason why this use case makes more sense)

[1]but I think the underrated problem with beamed power isn't just the low maturity of the technology, but that as soon as you start talking about sending power to earth via RF or laser you're going to encounter political opposition that makes objections to terrestrial datacentres seem tame.... [2]chips can in theory be replaced on orbit, but the "million satellite" filings are disposable. Replenishing propellant for a few large power stations, potentially on longer cycles, is a simpler task.

[pantalaimon]

> but solar cells and satellite structures have longer useful lives than inference chips

The limiting factor on the lifetime of any satellite is fuel. Especially for large structures that are influenced a lot by atmospheric drag and solar wind.

[notahacker]

Sure, but periodically refilling a propellant tank for a few large SBSP structure on-orbit involves less complexity than replacing racks of inference chips distributed across constellations of satellites as proposed by current filings. Which is why the latter structures are designed to be disposable and the former not.

SPSP proposals tend to operate in higher orbits than ODC proposals too, as they're less affected by latency and radiation, so their station-keeping requirements are less propellant-intensive.

[TeMPOraL]

> beamed power is lossy enough to require more panels[1]

What kills that is simply costs of land. You have to put these larger rectennas somewhere, and land ain't getting cheaper.

[notahacker]

Non-exclusive use of farmland or wasteland (or even - at least until maintenance complexity is considered - offshore) isn't a major barrier; we have many many miles of wires and pylons crossing farmland for regular terrestrial grids already. A rectenna looks more like a mesh than a set of panels: the idea is that the visible light spectrum passes through and the target microwave frequencies don't, so unlike a photovoltaic solar farm the land underneath is fine for farming. Nominally the land is safe to be occupied or passed through by humans too, although they might take some convincing. It becomes a problem when people start trying to get the rectennae banned...

[mr_toad]

> Non-exclusive use of farmland or wasteland (or even - at least until maintenance complexity is considered - offshore) isn't a major barrier

Not now, but with solar power output doubling every few years how long before we run out of land?

[notahacker]

Never. As the post you apparently quoted without reading said, we're talking about a rectenna composed of pylons and wires structured as a mesh that doesn't interrupt farming and can theoretically be offshore, not panels here

Space based solar power has much bigger challenges in gaining acceptance, proving the physics works in real world conditions and delivering on its promises than the theoretical possibility that there is absolutely no unoccupied region of land or sea