When generating electricity, energy is lost to friction in mechanical bearings (e.g. turbine or generator bearings) and as heat, through resistance in transmission wires.

If you were generating electricity in a low gravity environment, could the power station be designed to make use of the low gravity environment to reduce the above losses?

(This is not a perpetual motion question.)

  • $\begingroup$ What sort of power generation are you thinking about? Electric generators? $\endgroup$
    – Jack
    Jun 13, 2018 at 13:13
  • $\begingroup$ As far as I know, friction does not really apply when talking about gravity's effect on electricity. If you're in a microgravity environment, batteries and energy storage devices Funktion the same whether you're in deep space or low earth orbit $\endgroup$
    – Dragongeek
    Jun 13, 2018 at 13:19
  • $\begingroup$ I guess my question is, how much does earths gravity effect the rpm of an electric generator? $\endgroup$
    – S. Medina
    Jun 13, 2018 at 14:50
  • 1
    $\begingroup$ @Dragongeek many/most/all electricity generation sources on Earth involve big heavy things that rotate. Hydropower, Coal/Gas, as well as kinetic storage devices all have spinning things that convert flow to rotation which then is converted to AC power. There is certainly some friction in the bearings (mechanical, magnetic, etc.) supporting the weight of these against gravity. It may not be significant compared to other inefficiencies, but it's there. $\endgroup$
    – uhoh
    Jun 13, 2018 at 14:51
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    $\begingroup$ @S.Medina I think this is an interesting question! In addition to friction associated with bearings used to support the weight of rotating things against Earth's gravity, there is friction due to the air. This is particularly a problem when energy is temporarily stored in high speed rotating masses (instead of chemical batteries) as backup power or makeup power. I think with a little editing this question will be reopened. It's very possible someone with more experience here in SE will edit it for you to speed things up. $\endgroup$
    – uhoh
    Jun 13, 2018 at 14:53

1 Answer 1


Low or zero G makes it easier to use magnetic bearings, which eliminate friction losses from conventional bearings.

Gravity doesn't really impact the rotational speed of a generator: the energy spent on the upward half of the rotation (moving mass up) is compensated by the downward half.

Low gravity doesn't help with transmission losses. In outer space (depending on where you are, Earth orbit is too hot for this), you may be in an environment where you can use superconductors without active cooling, and that would eliminate the transmission losses.

  • $\begingroup$ Note: you'd need to be in permanent shadow and have any non-superconducting parts of your generator totally insulated for it to work. $\endgroup$
    – Jack
    Jun 16, 2018 at 11:06

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