6 Replies Latest reply on Nov 5, 2017 1:25 AM by dixon415

    Electricity over the air

    dixon415

      Is it really possible to transmit electricity over the air? To charge Bluetooth headphones or a Wi-Fi hotspot, maybe why not charge our mobile phones when connected to Wi-Fi?

       

      I have found one article to be inspiring and relevant to this discussion. Check it out by clicking here.

      Electricity over the air

      German student creates electromagnetic harvester that gathers free electricity from thin air

        • Re: Electricity over the air
          jw0752

          Hi Dixon,

           

          Electro-magnetic waves are sent through the air all the time. The problem that arises is the cost versus the gain. If they are not narrowly focused the waves spread out in all directions and quickly loose their energy. Every time you double the distance you get 1 fourth the power. While this is not so great a problem if you are just sending information as in radio broadcasts, if you are trying to send power you have to waste a lot of it to get a little to the target. The advent of electronics that use very little power have made this idea a little more practical in certain environments but still not ready for general applications like you mention.

           

          John

          4 of 4 people found this helpful
            • Re: Electricity over the air
              dixon415

              Yes, as you have mentioned rightly the issue lies in Cost spent Vs Energy gained. As we are now capable of charing phones without cables and adapters through wireless charging via Induction principles, I was wondering somewhere in the world, this idea of "Electricity over the air" has reached the commoners.

               

              Thank you, John. jw0752

               

              Dixon Selvan

            • Re: Electricity over the air
              Jan Cumps

              For practical applications this is not doable with a reasonal budget, efficiency.

              ubeam is trying this for years now, with loads of other people's money, without a practical application in sight.

              4 of 4 people found this helpful
              • Re: Electricity over the air
                DAB

                RF transmission is incredibly lossy.  You run into the 1/r^2 issue with all EM signals.  So you lose 75% at the first increment about 89% at the second incremental distance.

                 

                So you have to keep all of the devices very close to ensure a tuned circuit transfer.  Even then, the efficiency is very low.

                 

                DAB

                3 of 3 people found this helpful