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

Power Production

  1. Aug 9, 2010 #1
    Got an idea for something that I think with the abundance of bright minds here I will find the oversight that makes this idea NOT work. :)

    In short:
    Solar Collector - parabolic dish
    Focused light is directed into a solar generator device.

    The device is as follows:
    Quartz glass tube shaped in a full circle - ends are joined to form a complete circular cavity.
    At one point along tangent to the centerline of the tube, a straight section of tube of same diameter is joined - with its internal volume shared with the main circular tube body.
    At the junction where this straight tube meets the circular tube, within the circular section just immediately after the point where the straight tube meets it, two electrodes are installed.
    The inner wall of the tube is coated with a dielectric mirror coating. of which its inner tube diameter and the circular ring diameter maintains low angles of incidence to produce a component with total internal reflection.
    The assembly is drawn to vacuum and sealed.

    The two electrodes are joined to a high voltage power supply - something like a flyback transformer for a CRT television (appx 40KV) - this produces our "free electrons" within the assembly.

    One variation of the elecrode configuration could be that the electrodes are placed 180 degrees apart within the tube. I believe this assembly would actually behave as a capacitor and contain these free electrons once produced, but I'm not positive on that.

    Finally, this round tube is then wrapped with copper wire nearly its full circumference (only lacking the windings where the straight tube is joined.

    The power transformer is turned on providing a source for free electrons. Then the focused solar light is introduced.

    The question is, do the incoming photons from the solar collector/concentrator impart a velocity into the electrons to drive them around the loop?

    If so, the moving electrons will impart their magnetic field upon the windings around the loop and induce current flow in the coil.

    Of course this entire idea is based on the premise that these unbound electrons will absorb the incoming photons and produce velocity (momentum) into the electrons to drive them around the ring. And because they are "free electrons" they should be willing to absorb any photon that collides with them.

    There are many other design ideas I have for this and obviously this device, as described above, does not cover all of the bases for its final complete design, but whether or not it will do anything is based on how these electrons and photons will interact.

    If this is so, a very inexpensive and efficient generator could be produced, but it is all based on the idea that a free electron will absorb any photon and be accelerated as a result.

    From what I've read about compton scattering, it appears that an electron will happily absorb a photon and as a result, nearly 99% of the photon energy is transferred into the electron.

    This isn't just a pointless question either - I have the facilities to build every one of the components in such a device and will do so if my presumption here is correct. :)

    Thanks for reading this and I look forward to your responses!

    What am I missing here that will prevent this from working?

    -Ash Powers
     
    Last edited: Aug 9, 2010
  2. jcsd
  3. Aug 10, 2010 #2
    The list of reasons is extensive. To throw out a few of the simplest problems (neglecting the obscene complexity of the device and the costs/dangers there-in):
    1) Parabolic dish must always be pointing at the sun
    2) How exactly are you going to get free electrons from the transformer? How could that possible require less energy than you'd get?
    3) If the tube is coated with a mirror for 'total internal reflection,' how exactly would light get in (and what about after wrapping the entire thing in copper wire?)
    4) You want to randomly excited electrons, and use the induced magnetic field to generate electricity in a non-supercooled (and actually quite hot), highly resistive wire

    I think most people would rather just use a solar panel. Keep up the ideas, but maybe you should put those 'facilities' to some practical uses while you're cranking away :D
     
  4. Aug 10, 2010 #3
    Thanks for the reply - I left a lot of other information out as it wasn't pertinent to the knowing whether or not these free electrons will absorb the incoming light and be propelled through the loop.

    1) Building a heliostat is nothing difficult, I have the engineering experience to build whatever electronics needed to handle that.

    2) The transformer to be used, i.e. the potential needed to produce a sufficient density of electrons, isn't exactly known at this point, but could be mathematically determined and revised through empirical testing. The power it will require to provide these electrons would be minimal in comparison to the solar input of the collector - a 10KW solar collector (10^2 meter collector area) is the current design point. Sure it will take a bit of power to produce the electrons, but the energy going into the generator far surpasses this requirement. You give a little energy and get back many fold.

    3) The circular tube and straight inlet tube are coated internally for optimal reflectivity - the end of teh straight tube will not be coated and will be the inlet of the solar energy.

    4) The coil would obviously perform with greater efficiency if it were supercooled, but that would be a v.2 sort of affair and likely prove to be cost prohibitive for the gain. However, there will be heat involved within the generator, considerable amounts. The device can be housed within a chamber using a coolant system that maintans the assembly within thermal limits of the materials. The hot water coming from it could even be collected for residental use, thereby harnessing as much energy as possible from the solar energy you are collecting.

    Back to your point 2). It is my understanding that in a vacuum tube, much like a CRT in old-school TV's, a high-voltage transformer is used to produce the electrons which are guided electromagneticaly to points on the screen to excite the phosphorus and excite it to emit light that makes up the image you see. Even when you power down the TV, the tube is still highly charged - it acts as a capacitor. I'm not so sure that this capacitive state would provide the electrons needed for my application, but there are electrons stored that may be used just as effectively.

    Regardless, it is not difficult to produce free electrons within the tube - just look at the old vacuum tube experiments that were done which led to the understandings we have about the electron.

    The problem with a solar panel is its high cost and low efficiency. For every square meter of panel, it only converts 1000W of solar energy into about 150W. Even 1950 technology gasoline engines could match that efficiency. I sincerely fail to see how solar panels are really a practical solution - there has to be a more efficient, cost effective means to convert electromagnetic energy into electrical energy.

    The limitation with solar panels is due to their construct - the material it is made from cannot convert all frequencies of sunlight into electrical power. The idea to use free electrons to absorb all frequencies to light to increase their momentum/velocity and then use their magnetic field to produce current flow, if possible, should put solar cells to shame.

    Do you know if my presumption of the electron-photon interaction will produce the result I have been speaking of?
     
  5. Aug 10, 2010 #4
    1) its wonderful that you can make a heliostat, but its not wonderful for making a cheap, efficient, robust generator.
    2) One of the reasons we stopped using vacuum tubes, is because generating those electrons takes A LOT of energy, its a very inefficient process, not to mention you get a tiny tiny tiny amount of electrons. The amount of electrons you would produce would be negligible compared to the number of electrons in the valence band of a photovoltaic cell.
    3) no way can you put all of that junk in the center of high-efficiency parabolic mirror
    4) the resistance in such a large inductor would be tremendous. and super-cooling requires a ridiculous amount of energy and equipment (priced prohibitively).

    Solar panels aren't so great right now, but they're starting to improve fast--e.g. work at stanford (see: http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2814.html). You say they are high cost, but photovoltaics would be numerous orders of magnitude cheaper than what you're proposing.

    Generally when you're trying to improve on something that is already proven (e.g. generating electricity), you have to do it through simplicity, not outrageous complexity. See: http://www.jobyenergy.com/ for genius examples.

    But as far as the electron-photon interaction, yes. Photons will heat up electrons.
     
  6. Aug 10, 2010 #5
    Perhaps your view of the complexity of building this is not the same as my own. I've built far more complex systems before. The time and materials to build such a device isn't the issue.

    There is a lot more math involved which I have not gotten to at this point, there are other considerations that need to be resolved before even getting to that point. The question is whether or not these free electrons will be willing to absorb any frequency of light that is imparted upon them and propel them through the inductive loop.

    All of the other concerns you have do not deter me - they can be managed. But all of those considerations are a moot point if the electron-photon interaction I am speaking of isn't how it happens. Do you know if this is teh case or not?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Power Production
  1. Product States (Replies: 8)

  2. Pair production (Replies: 3)

  3. Inner products (Replies: 2)

  4. Pair production (Replies: 1)

  5. Direct products (Replies: 1)

Loading...