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Comment by saulrh | Hacker News Reader

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.

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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?

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.

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.

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?

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