Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Freight elevator efficiency?

  1. Aug 8, 2007 #1
    Hello all,
    I have probably a simple question for mechanical engineers. I would like to know the energy efficiency of real world freight elevators, going up with a speed of one meter per second. How about the best elevator's efficiency I could expect?
  2. jcsd
  3. Aug 9, 2007 #2


    User Avatar
    Science Advisor

    It will drastically depend on the motor used. As a rule of thumb for preliminary calculations, 85% is a good starting efficiency number for industrial motors (in my experience anyways).
  4. Aug 10, 2007 #3
    Thank you FredGarvin :)
    May be then.. would it possible to 'regenerate' most of the potential energy of the lifted freight, into electricity (e.g. with the same motor, only in reverse)?
    What could be the efficiency of this second step?
    If the round-trip efficiency could be more than 70%, then this would directly compare (and may be has other advantages, smaller capital cost(?), smaller environmental impact, more potential locations) with the main large scale energy storage technology, namely pumped-storage hydroelectricity?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook