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> If there was a viable low cost superconductor that worked at temperatures up to 50 degrees Celcuis and atmospheric pressure, the implications would include:

It's important to note that a superconductor is a superconductor not just as a function of temperature, but also the amount of current carried, the critical current density[1], and magnetic field strength[2].

If the superconductor has a really poor critical current density, and the indicated numbers seemed to suggest so, it might not be viable for a lot of interesting applications in electronics and similar.

[1]: https://en.wikipedia.org/wiki/Superconducting_wire#Important...

[2]: https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_...

>power transmission without loss. Very long range power transmission becomes viable and low cost (buried cables near roads?). For instance, solar energy transmitted in real time from where the sun shines to where it is dark or cloudy.

For practical purposes this is only true if the cost of the material and support systems for the superconducting transmission is substantially less than the cost of the power lost in the existing system. Existing power transmission systems are already quite efficient, and we don't bother making them more efficient with HVDC because the infrastructure costs don't justify the power savings. It's almost certainly the case that superconductor cable would be significantly more expensive than that.

What we really need is more capacity, which this material as presented doesn't seem to help with.

> What we really need is more capacity, which this material as presented doesn't seem to help with.

I thought one of the benefits of superconducting wires was that they could carry a lot more. Is that generally not true of superconductors?

I believe one of the properties of the alleged room-temperature suoercinductor is that it's only a superconductor at low currents.

Superconductors have zero resistance up to some quench current, so you can’t just put infinite current through a superconductor. If the quench current is low, the superconductor is not practical. Even practical superconductors might have a quench current only 4x what you’d put through traditional copper before the ohmic losses become too high.

I'm a civil engineer, and let me just say I'm extremely skeptical of several of these:

I doubt that there's ever going to be superconductors used commonly in long range power transmission. The economics just won't make sense, the conductive properties of the material are not the only ones that matter: (lifespan, toughness, flexibility, etc. matter a LOT.)

Fusion reactors will be a lot easier to construct when you don't need such ridiculous cooling needs, but I still don't get why we don't just build more fission reactors. They work great, and we could have been carbon neutral decades ago. You think fusion reactors will solve the construction cost problem?

Imaging and other sensors I think will be huge.

Man, mag lev trains aren't ubiquitous in the states because of the cost of running them. They are just almost impossible to build in the present political climate where the extreme cost of right-of-way acquisition through eminent domain needs and environmental regulation and litigation come into play.

It's already way too expensive to just build roads out of rock. No way we replace roads with magnetic rails.

> You think fusion reactors will solve the construction cost problem?

I don't think DT reactors will solve this problem. If anything, they will make it worse. The volumetric power density of a DT fusion reactor is going to be at least an order of magnitude worse than a fission reactor, for fundamental reasons involving limits on heat transfer across surfaces.

This is why people are excited about Helion, which sidesteps the problem by extracting energy from the plasma electromagnetically rather than as heat (heat is still dissipated, but it does not have to be run through a heat engine.)

BTW, for transmission, superconductors would be more interesting for buried power lines, where voltage is limited and heat dissipation is problematic. Sueprconductors are also interesting in aerospace, particularly for hybrid electric aircraft.

The MRI implications of this are huge. Imagine what cheap portable MRIs could do for the world.

I think they would be somewhat cheaper to build and considerably cheaper to operate, but a strong magnetic field is still difficult to deal with in practice. Would it really be an improvement over eg. CT?

Sorry, but "portable MRIs" makes no sense. Current high-temperature superconductors (HTS) can probably get you from 3 Tesla to 6 Tesla for commercial MRIs which means better resolution. But you still need magnets large enough to enclose a human body and the structural materials (steel) to withstand the magnetic forces. Also you need to keep the machine clear of metal objects or you have to shut down and restart the magnets which contain so much energy that it has to be released slowly and is a long and involved process.

It's pretty recent, but I see no reason something like this couldn't be iterated on? https://hyperfine.io/swoop/overview

I came to mention the same device

Even without superconductors, advances in permanent magnets make some innovation practical. Here's an article about a portable MRI that sells for $250,000[1]

[1] https://www.science.org/content/article/mri-all-cheap-portab...

Swoop is 5 gauss which is 0.0005 tesla. Compare that with my last MRI which was 3.0 tesla. It seems be used for some kind of brain imaging, neuroactivity, etc. but it won't be replacing regular MRI machines. HST magnets will get you 6 tesla MRIs in the next decade or two.

Edit: "65-millitesla" or 0.065 tesla.

A lot of options open up when you cam have an array of smaller magnets I think.

not really

- electronics need miniturisation, and wires - can it be made into wires? Can it do 10^11 features/chip? Can it form transistors? that's were most of the loss is currently.

- power transmission gets a little more efficient, and for long distance, which is already feasible with HV DC, it would be more efficient still. But in both cases, only if it's cheap enough.

- confinement is far from the only technical obstacle to fusion. The main obstacle is actually economics. It will simply never be cost effective compared to alternatives.

- Yes, smaller/simpler MRI etc is a real benefit.

- levitation itself is only a small piece of the puzzle, and again, cost.

The real benefits are in things like sensors, and current research where a strong magnetic field, or the ability to rejecting one, is needed.

Your fusion point doesn't make any sense. The economics aren't great because the equipment required is expensive. A big part of that with current popular designs is the magnetic confinement. Swap out liquid nitrogen-cooled superconductors for RTSC and that piece of the puzzle becomes much more appealing, for the exact same reason MRI becomes smaller/simpler (which you admit is viable in the next point).

I'm not convinced RTSC will be immediately applicable in fusion reactors. Wendelstein 7-x is using helium cooled superconductors even though nitrogen cooled superconductors exist, but apparently they lack some necessary properties.

What if the RTSC is too brittle to make wires out of it or something like that?

I said the magnets are not the only obstacle or complex technology. They're not even the major obstacle or expense.

But to touche your point, if ambient superconductors, then long distance transmission from remote solar panels, apparently.

There's just no way fusion is ever going to compete economically as mainstream energy, with ever cheaper solar (and wind, tide, etc), geothermal, and improved fission, at least with the current high-temperature plasma-confinement, and especially D-T, 'chemistry'