3 ms·

I think you mean Superconducting Magnetic Energy Storage (SMES). Supercapacitors are a different thing. https://en.m.wikipedia.org/wiki/Superconducting_magnet

• jakeogh 9y ago
  Rather unlikely that parent confused the two. Supercaps are nice if you don't mind trading their ~<1/5 energy density (mass, volume) of batteries for their excellent cycle count. Clearly not grid scale since batteries barely are.
  • Dylan16807 9y ago
    1/5 takes quite a stretch, or comparing to especially low-density batteries. Maybe in a couple decades they'll be there, but my understanding is that high-end supercaps are currently 25x less energy dense than a lithium ion battery.
    • jakeogh 9y ago
      ~9Wh/kg for the best supercaps, compared to the old (and still standard) lead-acid maxing out around 42Wh/kg. Li-ion maxes out at amazing 265Wh/kg but they are always? small and scaled up by putting many in parallel... and if you damage one it's emergency fire preparedness time.
      • Dylan16807 9y ago
        But if you have just about any concern for density, you're not using lead-acid. Not when that's another 5x worse than other batteries. I'm willing to bet that most lead-acid users would happily switch to cheaper supercaps if they existed.
        • jakeogh 9y ago
          Agreed. When supercap J/$ hits lead-acid levels the J/kg difference wont matter and most people using lead-acid will happily trade 1/4th the energy density for near infinite recharges.