i have discovered an alternative fo powering solar panels...

xdreamer03
xdreamer03 Registered Users Posts: 6 ✭
in Solar Beginners Corner #1
in just messing around, i havee discovered that solar panels can be charged with led light. -m. bryan hale 2/28/13
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  • xdreamer03
    xdreamer03 Registered Users Posts: 6 ✭
    #2
    Re: i have discovered an alternative fo powering solar panels...

    so in "light" of that why cant we create a unit consisting of rows and stacks alternating led and solar panels? jw
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
    Re: i have discovered an alternative fo powering solar panels...

    Welcome to the forum.

    What powers the LED lights that power the solar panels?

    Do you know what "perpetual motion" means?
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  • xdreamer03
    xdreamer03 Registered Users Posts: 6 ✭
    #4
    Re: i have discovered an alternative fo powering solar panels...

    the led light. so take a solar powered yard light, and shine a single led flashlight into the solar panel and the yard light comes on.
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  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    #5
    Re: i have discovered an alternative fo powering solar panels...
    xdreamer03 wrote: »
    so in "light" of that why cant we create a unit consisting of rows and stacks alternating led and solar panels? jw
    You can, but it will be a net consumer of power. The amount of power that the LED's will consume will be several times more than what the solar modules will produce.

    Nice try, though. :D
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  • xdreamer03
    xdreamer03 Registered Users Posts: 6 ✭
    #6
    Re: i have discovered an alternative fo powering solar panels...

    the dollar store has these dancing flowers, solar powered so the petals move when powered. the energy created by the solar creates a charged magnet and spring. my 2.00 led flashlight shining directly into the panel makes the flower dance.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #7
    Re: i have discovered an alternative fo powering solar panels...

    I usually wait till my neighbor turns the porch light on to walk his dog, then I turn a panel towards his house to get some of that Free energy. Of course it's all dependent on how long the dog takes to do his business on the amount I get.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
    Re: i have discovered an alternative fo powering solar panels...
    xdreamer03 wrote: »
    the led light. so take a solar powered yard light, and shine a single led flashlight into the solar panel and the yard light comes on.

    You haven't answered the question: what powers the LED light? It needs electricity. In your example the power is supplied by the batteries in the flashlight.

    Yes, you can get output from a solar panel illuminated by any light source, not just sunlight. But you don't have to put new batteries in the sun every so often or pay the utility bill for it or refill the fuel tank.
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  • xdreamer03
    xdreamer03 Registered Users Posts: 6 ✭
    #9
    Re: i have discovered an alternative fo powering solar panels...

    i dont know how much power is created by the solar panel but its enough to charge the battery inside the yard light for like 4-5 hours use. so i know its the idea of perpetual motion. i just imagine that if you wire the panel to the light bulb and just start the process by shining another light into the panel, wouldnt it be self sustaining.....i have no training or schooling in this field so i dont have alot of answers.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #10
    Re: i have discovered an alternative fo powering solar panels...
    xdreamer03 wrote: »
    i dont know how much power is created by the solar panel but its enough to charge the battery inside the yard light for like 4-5 hours use. so i know its the idea of perpetual motion. i just imagine that if you wire the panel to the light bulb and just start the process by shining another light into the panel, wouldnt it be self sustaining.....i have no training or schooling in this field so i dont have alot of answers.

    Nope.
    If you wired the yard light directly to the batteries that are powering the LED flashlight it would last a lot longer.

    Batteries power LED light: some power is lost to heat (even though you don't feel it it's still "heat"). Never is 100% of the energy turned into light. At best 95% efficient.

    Light falls on solar panel. At best it manages to convert 18% of the light into electrical energy.

    Energy from solar panel recharges battery: more losses in charging the battery. At best it will be 85% efficient.

    So end-to-end you are actually losing most of the energy you started out with.

    This is why no "perpetual motion" device of any kind can ever work: there are absolutely always losses that take power from the initial "source" and do not contribute to the end "work". It is totally impossible to overcome this, no matter what the shysters say.
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  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    #11
    Re: i have discovered an alternative fo powering solar panels...
    xdreamer03 wrote: »
    i dont know how much power is created by the solar panel but its enough to charge the battery inside the yard light for like 4-5 hours use. so i know its the idea of perpetual motion. i just imagine that if you wire the panel to the light bulb and just start the process by shining another light into the panel, wouldnt it be self sustaining.....i have no training or schooling in this field so i dont have alot of answers.
    No. As I said, the power necessary to run the light bulb will be much more than the power the solar module produces. Even if you did not remove any energy from the system (and if you can't remove energy from it to do work, what's the point?), it's not sustainable. A solar module converts only about 20% (max) of the light energy that falls on it into electricity. I don't know how efficient the best LED's are at converting electricity into light, but it's less than 100%. And then there's the loss to resistance of the wires. Every time you send energy around the loop, you lose over 90% of it. In your experiment you are using far more energy from the batteries in the flashlight than the solar cells you hit with the light are producing.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,660 admin
    #12
    Re: i have discovered an alternative fo powering solar panels...

    Those solar yard light panels are only around 10% efficient... So every conversion (light to panel to LED to light) will cost you well over 90-95+% in conversion losses... Add the NiCad cells which are around 40-60% efficient, even less.

    What you are seeing as available energy for doing work, it really possible because the work being done is performed very efficiently (LED lights are round 0.050 to 1 watt power). It takes a lot of sun (1,000 watts per square meter) times 2-6 hours per day (full noon time equivalent sun) times the efficiency of the panel (10%) times the efficiency of the battery storage (call it 50%) to get that little 100 mWatt light to run over night. And the light from the LED shining on the surface is probably 1/10,000 the power of noon time sun equivalent.
    BB. wrote: »
    I don't have a panel to test myself--But testing indoors is going to be difficult to see if the panel is good...

    --some numbers:
    • sunlight on an average day ranges from 32 000 to 100 000 lux
    • TV studios are lit at about 1 000 lux [i.e. 1000 lumens
    per square metre]
    • a bright office has about 400 lux of illumination
    • At sunset and sunrise, ambient outdoor light is also about
    400 lux (if the sky is clear).
    • moonlight represents about 1 lux
    • starlight measures a mere 0.00005 lux

    A bright office is about 400/100,000 or 0.004 (0.4%) of full sunlight. At those light levels, the self discharge of the solar cell (there is some internal resistance between +/-) might keep the output voltage from reaching Voc (internal leakage current).

    If you have a 100-500 watt flood light--you might try shining that at the panel.

    Also, what is the short circuit current (multi-meter set to Amp/Current mode)?
    • 5.94 amps * 0.004 = 0.024 amps or 24 mAmps (not very much current)
    -Bill

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • xdreamer03
    xdreamer03 Registered Users Posts: 6 ✭
    #13
    Re: i have discovered an alternative fo powering solar panels...

    wow .. you guys know your stuff, here i thought i was on the verge of discovery. thanks for taking the time to explain all this to me.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,660 admin
    #14
    Re: i have discovered an alternative fo powering solar panels...

    It is OK--Lots of what we "explain" around solar energy is really hitting a lot of subjects on conservation. It is almost always cheaper to conserve power than it cost to generate it (especially with off grid solar power).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #15
    Re: i have discovered an alternative fo powering solar panels...
    Cariboocoot wrote: »
    Yes, you can get output from a solar panel illuminated by any light source, not just sunlight.

    We lit a big bon fire one night and it brought the Classic 150 out of Resting to Bulk MPPT. The panels got up to 90 volts and put out 23 watts from the light from the bon fire :D
    --
    Chris
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #16
    Re: i have discovered an alternative fo powering solar panels...
    ChrisOlson wrote: »
    We lit a big bon fire one night and it brought the Classic 150 out of Resting to Bulk MPPT.

    I hope you didn't light the bonfire on top of the panels out of frustration over their winter performance. :-)
    More seriously, how far were the panels from the fire?
    Were the panels aimed generally in that direction or could you have gotten more output with a bonfire tracker mount?
    SMA SB 3000, old BP panels.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #17
    Re: i have discovered an alternative fo powering solar panels...

    The panels are tilted up almost vertical for winter and they were directly facing the bonfire, but probably 50-60 feet away.
    --
    Chris
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #18
    Re: i have discovered an alternative fo powering solar panels...

    aren't you worried about getting a film of smoke aka carbon on the pvs? also more importantly most of the light spectrum from a bonfire is in the infrared range and not so much into the visible so the panel heating will be great and maybe greater than the sun if the fire was as big and hot as you indicate. there's a reason aluminum siding melts on homes close to another home on fire. be careful.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #19
    Re: i have discovered an alternative fo powering solar panels...

    We didn't do it on purpose and I didn't even realize the panels would put out power from the bonfire. We lit the bonfire for the grandkids to enjoy - not thinking about the solar panels.

    It didn't hurt the solar panels at all. They still work fine. Just happened to remember it when 'coot mentioned solar panels will make power from any light source.
    --
    Chris
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  • Thom
    Thom Solar Expert Posts: 196 ✭✭✭
    #20
    Re: i have discovered an alternative fo powering solar panels...
    ChrisOlson wrote: »
    We didn't do it on purpose and I didn't even realize the panels would put out power from the bonfire. We lit the bonfire for the grandkids to enjoy - not thinking about the solar panels.

    It didn't hurt the solar panels at all. They still work fine. Just happened to remember it when 'coot mentioned solar panels will make power from any light source.


    --
    Chris

    So I should put a solar panel in my wood stove at night . When I get up batteries would be fully charged ! :0) Ha ha

    Thom
    Off grid since 1984. 430w of panel, 300w suresine , 4 gc batteries 12v system, Rogue mpt3024 charge controller , air breeze windmill, Mikita 2400w generator . Added 2@ 100w panel with a midnight brat 
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #21
    Re: i have discovered an alternative fo powering solar panels...
    Thom wrote: »
    So I should put a solar panel in my wood stove at night . When I get up batteries would be fully charged ! :0) Ha ha

    Thom

    Only if you have an inefficient bright flame in your wood stove. A nice glowing bed of wood and embers will produce mostly infrared and so will not produce much power from the panel. :-)
    SMA SB 3000, old BP panels.
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  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    #22
    Re: i have discovered an alternative fo powering solar panels...

    Yeah....now if we can just find a panel with a 1200 degree rating..................
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  • boB
    boB Solar Expert Posts: 1,032 ✭✭✭✭
    #23
    Re: i have discovered an alternative fo powering solar panels...
    TnAndy wrote: »
    Yeah....now if we can just find a panel with a 1200 degree rating..................


    Probably not exactly what you were looking for, but .....

    http://jxcrystals.com/GaSb/4sale5.pdf
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #24
    Re: i have discovered an alternative fo powering solar panels...

    andy,
    you forgot to add, that is cheap.
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  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    #25
    Re: i have discovered an alternative fo powering solar panels...
    TnAndy wrote: »
    Yeah....now if we can just find a panel with a 1200 degree rating..................
    You jest, but about a year ago I went to an IEEE seminar on the reclamation of waste heat energy at power plants. The presenter's company is (or was - I haven't heard any more about it) developing a semiconductor device which produces DC power similarly to PV, but from conducted/convected/radiated heat. The plan is (or was) to mount banks of these devices in the thermal output streams of power plants.
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #26
    Re: i have discovered an alternative fo powering solar panels...
    ggunn wrote: »
    You can, but it will be a net consumer of power. The amount of power that the LED's will consume will be several times more than what the solar modules will produce.

    Nice try, though. :D

    Here is another brainstorm: If you are near a grid-connected location but the cost of running wires to your place would be too high, use the grid to power a really bright light aimed directly at your solar panels. :-)
    SMA SB 3000, old BP panels.
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  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    #27
    Re: i have discovered an alternative fo powering solar panels...
    inetdog wrote: »
    Here is another brainstorm: If you are near a grid-connected location but the cost of running wires to your place would be too high, use the grid to power a really bright light aimed directly at your solar panels. :-)
    I once told my wife that if she got bigger tires for the rear wheels on her car she would get better gas mileage because the car would always be rolling downhill. She bought it - for about 3 seconds. Then she hit me.
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