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I did a back of the napkin calculation a while ago regarding how many car lengths you’d need to put in LEO to have an unbroken traffic jam in orbit and the result was surprisingly comparable to the number of cars we’re currently producing. If you were “simply” launching wire instead I’m sure you could get enough material up there in much fewer launches. I’m curious as to how you would construct such a loop since you’d need to station keep it somehow while it’s inoperable.

You can build it in sections because the wire itself is travelling at orbital speeds. That's actually what makes the whole thing work. Running a curent through that creates an electric field. You would probably encase the whole thing and contain it with a magnetic field. You would then build things on top of that casing.

What kind of cable material do we have that can support its own weight for that many miles vertically?

My man said copper XD

Copper is not strong enough, and steel isn't quite strong enough to hold itself up with constant cross section.

Carbon fiber is, or you could just have a tapered steel or aluminum cable.

The loop could be anything as it's under zero G. You'd need counterweights above it.

You only get access to the equator without some kind of bizarro maglev hula hoop contraption which would level a country if anything went wrong, and the equator doesn't really need help with solar or solar storage as PV+CSP works quite well there.

Going with what you’re saying, a better use of the tech would be to supply electricity to places that currents rely on generators. There are islands that use diesel generators md burn a mass of fuel where electricity could be beamed in, Rarotonga for example.

So I don't think fossil fuelds will completely go away. It's just that most use cases will be eliminated once there is a cheaper and equially suitable method of power generation.

I strongly believe in the future of solar power in general because it's relatively low-tech and reliable. There are no moving parts (other than maybe turning an array to face the Sun while it moves across the sky but this isn't strictly required). So solar power can provide power in a lot of places where it's either impossible or infeasible to build infrastructure (eg remote places, war zones).

But once solar power source (or something else) is cheaper than burning oil, gas or coal you can use that power to make fossil fuelds by sequestering carbon from air. That's not that difficult but we don't generally do it because it makes little economic sense. But this method would make fossil fuelds essentially carbon neutral.

So there are vehicles that won't make sense to be replaced with EVs. Likewise, there are places where burning fuel may still make snese. Solar power may not make sense in jungles or hurricane zones so there may be continued use of generators. I can't speak to the specifics of Rarotongo. In general though, I think the technology and infrastructure will be truly transformative on a massive scale.

Not just little islands either.

I was at a radio transmitter[1] on the West Coast of Australia the other day. It's the largest low frequency radio in the Southern Hemisphere, used by subs and military stuff.

The facility, which is 6 kilometres from a regular town, and has three diesel generators producing 18,000,000 watts of power, burns through 26,000 litres of diesel PER DAY. It's been doing that 24/7 since 1967. (There was a sign proudly stating as much)

We do a TON of stupid stuff, regularly.

[1] https://en.wikipedia.org/wiki/Naval_Communication_Station_Ha...

If it's stupid, but it works...

Now, how expensive - and how big - would an equivalent solar array be? Don't forget maintenance costs, including technicians.

Once all that is cheaper and just as reliable as their generators, only then will there be a discussion on replacement.

But in general, I agree that it should be done.

Solar is the lowest maintenance source we have, so yeah, make sure to add maintenance. (It's more expensive with batteries, but compared with diesel, it's ridiculously cheap.)

What about maintenance of the physical structure? PV panels have no moving parts but:

1. The inverter and other electrical systems do fail (surprisingly frequently).

2. Solar is very spread-out: maintaining a geographically large facility is not trivial (vegetation, water drainage, cables etc.)

3. Batteries also require maintenance, and are an inherent part of any independent PV installation (if the site relies on the grid, it is no longer independent).

Out of curiosity, what kinds of things you assume I was talking about when I talked about solar power maintenance costs?

> Now, how expensive - and how big - would an equivalent solar array be? Don't forget maintenance costs, including technicians.

For an easy point of comparison, there actually is an 18MW solar array under development in western Australia as part of phase 0 of the Yuri project [0] (the goal of that project is to produce hydrogen for ammonia production via electrolysis instead of steam methane reforming). This is apparently around 23 hectares (57 acres), at a cost of A$24-33m in capital expenditures, and A$0.5-1.5m in annual operating expenses [1].

For comparison, let's suppose diesel is A$2 / liter. 26,000 liters a day, for 365 days a year, is A$19 million, every year, just for fuel costs. Wait, you might argue, fuel prices are inflated this year. Okay, historically it might have been closer to A$1/L, for about A$10 million per year. Breakeven is therefore somewhere in the ballpark of 2-4 years, which is absurdly low for a project of this scale.

[0] https://gateway.icn.org.au/project/4938/yuri-phase-0

[1] Page 28-29 of https://arena.gov.au/assets/2020/11/engie-yara-renewable-hyd... -- capex estimate is A$70m. If you remove the capex of building the H2 plant, you're left with A$33 million. If you just consider the PV component (34% of the overall capex estimate), then you get A$24m.

> Now, how expensive - and how big - would an equivalent solar array be?

Surely a 6km cable is the solution?

I think the military want more of a guarantee they'll have power 24x7. They want better uptime than the public grid.

They're allowed to keep the backup gennies while connecting to the grid, especially when the grid is so much cheaper it will pay for itself in the 99.9% of the time it's working.

It's not like hospitals and data centres refuse grid connections and run entirely on the backups.

Oh, I agree. But of course none of this is supposed to make sense. Someone, somewhere is making a lot of money the way things are now. Why change it?

... that wind solar battery can't do better?

This will absolutely work (and unlike beamed power, can provably avoid being used directly as a weapon by malicious actors); but, when you get to the scale "chonky enough you can attach a cable down to ground level", you might as well just build on the ground in the first place. A few square meters cross section is enough for a global HVDC grid using boring copper and/or aluminium, the losses aren't worth caring about given how cheap PV is even now.

Active support towers going up, that may work (if we solve the engineering issues, AFAIK nobody has tech demoed it yet), as those don't need to be supported by the cable, meaning the cable can be much smaller.

Building up is vastly more difficult than hanging something.

The best engineering on earth is still under a km in compression. To hang a steel cable 150km all you have to do is make it skinnier towards the bottom.

The engineering issues of the bit at the top might be a bit eye-watering. A 100% reliable maglev sled supporting 100s of tonnes coasting on a catenary supported by centripetal force sounds like a recipe for the world's largest whip.

Launch loops start to sound less scifi as a space megaproject (although then we're back tosuper weapons)

> All of this requires no new physics, no magical materials (eg space elevators do) and are just (admittedly massive) engineering projects.

Dragging wire down from space to earth would require space-elevator level of tech.

And I'm pretty sure microwaving earth's industry's worth of electric power thru the atmosphere wouldn't be any easier. Might even cause atmosphere warming all on its own.

wow this is such an incredible idea

reminds me of the earth-moon fire pole

https://what-if.xkcd.com/157/

So this clearly wouldn't work but it is a fun thought experiment. Thing is, there are places that it would work. Pluto and Charon notably are tidally locked to each other and have muich lower gravity and much lower distance (~12K miles).