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

Electricity from sea waves

  1. Jul 11, 2014 #1
    why can't electricity be generated from sea waves which are available through out the year.

    What is required for generating electricity is a source of energy that can rotate a turbine, which the sea waves are definitely capable. So what is the hurdles faced in this direction generating electricity.

  2. jcsd
  3. Jul 11, 2014 #2


    User Avatar
    Science Advisor

    It can be, and there are efforts in place to do just that. Check out the Wikipedia article on Wave power.
  4. Jul 12, 2014 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    One of the first jobs I had after graduating college was working for a small engineering firm consulting on a wave-energy generation project. This was 30+ years ago.

    Although waves are present 'all the time', they are variable in height and direction throughout the year. The generating array must be able to adapt to the change in the direction of the waves, which complicates the mooring design. Also, once a wave has generated some electricity, you've still got to get the electricity ashore. Just like with wind turbines, the variability of the winds and the waves means that the generated power is constantly fluctuating, which is not desirable.
  5. Jul 12, 2014 #4
    Can't the turbine be restricted to rotate at a minimum speed i.e the minimum power which is always available.

    I think wind may not be there always with the wind mill, but sea waves never stop, they can fluctuate with distances from the sea shore. I see sea waves as the only source that we see in nature which act like a perpetual machine.
  6. Jul 12, 2014 #5


    User Avatar

    Staff: Mentor

    Waves do stop now and then. Tides don't.


    But in general you are neither first, nor the last to think about harvesting waves power. I remember reading about them in seventies, and I am quite sure the idea appeared much earlier. As I see it mentioned now and then, I am more than sure people did a lot of research and if the thing is still not popular and widely used, it most likely means it is technologically challenging. Doesn't make it impossible to use - just the price of the energy can be too high.
    Last edited: Jul 12, 2014
  7. Jul 12, 2014 #6


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    If we are talking about wind turbines, how exactly do you restrict a wind turbine to rotate at minimum speed? If the wind doesn't blow, you can't spin the turbine.

    Sorry, but you are not clear when you say 'sea waves never stop'. We also don't discuss Perpetual Motion at PF, either.

    The wave height is a key measure of how much power can be extracted by a wave generator from the sea. If you are dealing with waves which all have only a small height, you can't generate much power. In fact, a lot of the studies done with the wave generator project I was involved in had to do with assessing which areas around the world had waves of sufficient height for a significant part of the year which would allow for the generation of a certain minimum amount of power. Not every place studied could meet the criteria chosen.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Electricity from sea waves