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Comment by QuadrupleA | Hacker News Reader

Can someone with field expertise explain the implications if this material were real / replicable / cheaply manufacturable? I see a lot of breathless excitement in these comments, as if free energy and perpetual motion machines are right around the corner, but from the few details I've delved into it's more like the electric grid might get 10% more efficient, MRIs might get a little cheaper, etc.

What are the exciting and apparently obvious applications that have everyone so excited? Is it a fusion / tokamak containment thing, that the cost of cooling current superconducting magnets is one of the big barriers to net energy generation?

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Transmission loss is a real and important reason why you can't, say, cover the Sahara with solar panels to get unlimited free energy for mainland Europe and Africa (barring all the logistical challenges of actually pulling something like that off). This is because you lose a significant amount of energy just by moving it from one place to another.

With RTP superconductors, you get near perfect transmission from the site of energy production to the site of consumption. You could put wind turbine in remote sections of Montana and power up Chicago, something which previously would have been impossible.

Sahara solar panels were economically viable according to multiple studies, and there have been some limited plans made, but it has turned out politically non viable so far. Transmission losses are smaller than often assumed.

From what I've read, grid transmission losses are something like 5-10% - e.g. this page (https://www.eia.gov/tools/faqs/faq.php?id=105&t=3) cites 5% in the US. Fine and nice, but seems incremental, not earth shattering, and I wonder about the logistics / ROI of manufacturing thousands of miles of LK-99 cables to achieve that. But maybe I'm missing something.

The losses increase with distance, and decrease with higher voltages, which is why most cross country transmission happens at 740kVAC. But still, the energy you're using in your day to day life is almost always produced with 50-100miles of where it's consumed, because transporting it longer distances make losses uneconomical.

At long distance, the transmission losses are so uneconomical – that they never got built in the firt place. This is why you shouldn't look at current loss numbers, which already weeded out what was not feasible before.

Now, if transmission losses are near-zero, then yeah – you'd still get the same power for the same price & losses (for other reasons), but from 500-1000 miles away instead of 50-100 miles. Residential customers won't notice anything immediately because they'll pay the same due to initial capital costs and stuff. But decades down the line it would slowly, invisibly transform everything around you.

The BIG change is if this supports high magnetic flux densities, in which case literally everything that depends on magnetism or magnets or electromagnets gets an order of magnitude better - ten times as much power per unit of heat disappeared and ten times as much power per unit of mass or volume or just ten times more powerful. Remember how battery energy density increased by a factor of five (nicads -> lithium-ion) and we suddenly had quadcopters and flashlights that could burn paper at ten paces and handheld vacuum cleaners the size of a soda can that could suck pet hair out of shag carpets and cars running off batteries? Imagine that happening again.

But wait - modern electric motors, for example, are something like 80-95% efficient (https://en.wikipedia.org/wiki/Electric_motor#Efficiency), which implies there's not a ton of room to grow. Do superconductors somehow enable 10x more torque output for the same watt of electricity? Or is it that you could have a small motor in the palm of your hand that can consume huge amounts of electricity and produce enough torque to crack a diamond?

They're far more efficient than a combustion engine, but electric motors and associated controllers/inverters do generate heat, and lots of it. DIY electric car conversion hobbyists struggle with this big time, for example. Cooling loops w/ pumps, fans etc. It's not as bad as the battery pack, but still a thing to design around.

I get the impression there's room for improvement esp in the inverter space.

Cars of course being only application of electric motors. I'm no electrical engineer, but I gotta think stuff like generators must have challenges?

The latter. Motor losses are in large part due to resistance in the windings. Going from 95% efficiency to 99% efficiency means 1/5 as much heat output per unit of energy delivered, which means if your motor is thermally limited (which many are these days!) you can push five times as much power through it without it burning itself up. Similarly, increased achievable magnetic flux means a smaller motor can achieve greater torque and power so it can convert more electricity into movement.

When the heat generation (inefficiency) is the main limiter in the technology, increasing the efficiency improves performance, rather than just saving power.

The electric motor limitations come from heat, so increased efficiency = increased strength. That 5-15% + work is what melts the motor when going beyond the rated load. I'm not familiar with the superconductors/electrical engineering but I think if no work is performed (motor is stalled), the motor will not get hot, basically just acting as a magnet.

From what I understand it is the same with computer chips, the biggest obstacle the chip companies have is heat generation; the chip gets too hot with the smaller designs. So less heat generation = faster chip.

Autonomous drones (for delivery and stuff) are extremely limited by the very low battery life. They fly around for 20 minutes and are done. Any complication and the battery runs out. So higher efficiency = longer battery life = more capabilities.

Nuclear fusion reactors also apparently benefit from higher temperature superconductors because it is hard to keep them so cold in a reactor. I know nothing about that though. To me it seems like 100 K or 300 K are very different from 100m K regardless but idk lol.

Avatar 3 merchandise will definitely include floating rocks of Unobtanium.

For some reason what my brain keeps imagining is pulling out a drawer of a cabinet and it being perfectly silent and butter smooth because it uses mag-lev instead of wheels.

Mag-lev based bearings might be nice too.

That's already possible.

Transporting solar energy from deserts.

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