A science-fictional idea for a geo-scale, lacework power plant
20.48, Tuesday 24 Jan 2023 Link to this post
The temperature difference across the U.K. yesterday (600 miles) goes from 11C in Scotland to -8C in the south east of England – a gap of 19C (34F).
Which seems like a lot?
Anyway I was wondering, if you could somehow short circuit that, could you generate energy from the heat difference?
It’s a bit of a brain-fart idea. I guess what you’d need is really, really good heat conductors… like: diamond. Diamond is a great conductor of heat. Apparently diamonds are known as “ice” because they’re cold in your hand if you hold enough – they conduct your body heat into the air really efficiently. Half-remembering here, but I vaguely recall hearing: if you had a diamond ashtray in your palm and you stubbed out a cigarette, it would feel like stubbing it out on your skin.
Anyway: so if you could spin a solid diamond pipe hundreds of miles long, you’d get a heat difference between your local end and ambient temperature, and maybe you could use that to drive a turbine or something, and make electricity?
Well why use heat? Go direct to electricity.
There’s something called an electrodynamic tether which is a long cable that hangs off satellites. It has been tested a few times. It takes advantage of the coupling between current, movement through a magnetic field, and force (the Lorentz force).
You hang the tether out of the back of a satellite, dragging it through Earth’s magnetic field, and use it in a couple of ways: either you pass a current through it, in which case it propels (or brakes) the satellite; or you take advantage of the changing magnetic field and generate electricity.
So imagine an electrodynamic tether but it’s not hanging from a satellite, it’s draped across, say, the whole of Canada. What would happen?
I mean, I don’t know. BUT: I do vaguely recall that normal EM flux across the breadth of Canada is large enough such that it’s hard to have a single electrical grid?
It’s worse during geomagnetic storms, caused by ejection of plasma from the Sun: the Carrington Event in 1859 is the biggest recorded geomagnetic storm, and:
The operators of the telegraphs reported receiving electrical shocks, telegraph paper catching fire, and being able to operate equipment with batteries disconnected. (Source: The Conversation (2022).)
It would likely be catastrophic to get a storm of that scale today.
But there are always geomagnetic storms of some magnitude, right? There are always induced currents in the grid somewhere?
And then then’s an energy harvesting technique called RF harvesting:
electromagnetic energy is abundant in space and can be retrieved without limit. Electromagnetic waves come from a variety of sources such as satellite stations, wireless internet, radio stations, and digital multimedia broadcasting. A radio frequency power harvesting system can capture and convert electromagnetic energy into a usable direct current (DC) voltage.
So let’s add room-temperature superconducting materials to the mix.
As diamond is to heat, superconductors are to electricity. Now we don’t have any room-temperature superconductors yet, but let’s say that DeepMind AI researchers decide that after solving Go, protein folding, and Tokamak fusion reactor plasma wrangling, they’ll have a go at chemistry and metamaterials…
…and they somehow engineer a superconductor that doesn’t need to be actively cooled, it’s all exotic surface properties or something, so it’s a passive structure, which is at the very least not impossible, and then: you weave the superconducting wires using a molecular 3D nano loom or something, just print them out hundreds and hundreds of miles long.
Pretending for a second you had that, could you do significant RF harvesting from the everyday variance of the Earth’s magnetic field as driven by the Sun?
You could prototype this with cooled superconducting cables but leave off the EM shielding I guess.
Now imagine a lacework of these superconducting cables over a huge region.
It would be kind of a geo-scale dream catcher for solar EM flux – drape it over the landscape and it would be a vast and diffuse power plant; plug into it from anywhere to tap free electricity. Generator implementation details left as an exercise for the reader.
(Any physicists capable of running the numbers on this? We should publish!)
Now this is a pretty science-fictional idea though I doubt it’s capable of carrying a story on its own.
One of my dreams is to contribute a sci-fi trope to the canon, like space elevators or tractor beams or rolling roads.
So if you’re an author and you have something on the go, please work in the geo-scale EM lace as the default power source, just as like background texture or something, and let’s get it into a few stories, and maybe a kid will read it and in a few decades we’ll have this for real, or maybe not and that’s cool too, but please give it a better name.