Possible Duplicate:
Are tidal power plants slowing down Earth's rotation?

I've heard that there are turbines converting energy from tidal waves. Tidal waves are created by the moon's gravity, so I assume the energy gained by the turbines is taken from the moon's potential energy. My question is; How many watt hours can we harvest from tidal waves before the moon falls down on top of our heads.


marked as duplicate by dmckee Oct 16 '11 at 19:05

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 1
    $\begingroup$ Welcome to Physics.SE! There are already a number of question about the tidal angular momentum transfer on the site which might help you. Note, however that the tidal interaction is transferring some of the Earth's angular kinetic energy (and angular momentum) to the moon, so it pushes the moon out not in, so the answer to your title question is "never on account of the tidal interaction". $\endgroup$ – dmckee Oct 16 '11 at 19:05
  • $\begingroup$ For the those who don't want to click, the answer is that the moon is slowly moving away from the Earth, not getting closer. The Earth's rotation is progressively slowing, which is fueling this movement as well as the tides. If the moon's revolution was faster than the Earth's rotation this would be reverse, but obviously a day is shorter than a month. I was about to leave an answer since this is such an easy one. $\endgroup$ – Alan Rominger Oct 16 '11 at 19:09

Browse other questions tagged or ask your own question.