8-11 volts out of covered solar panel

Discussion in 'General Electronics Chat' started by spinnaker, Nov 9, 2012.

  1. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    I have a new 40 watt solar panel that is replacing an old beat up panel for my signage solar lighting project.

    I was testing the panel and get the rated voltage + with no load. That is not the issue,

    The problem is when I cover the panel both front and back, I am still getting between 8-11V out of the panel. Plus I can see it climbing!

    what is going on here? Does the panel have that much capacitance?

    It' couldn't be so sensitive that it could still produce a voltage even though covered by thick cardboard could it? ;)
  2. crutschow


    Mar 14, 2008
    Is this in sunlight?
    Does it still have voltage at night?
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    Surprised me also: Normal output is 4 + kW, on overcast rainy day was still producing 1 kW. Also starts producing before sun hits horizon.
  4. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    Yes it was.

    Once the sun went down and I connected it to my panel, it operated more as expected.

    In the evening it was measuring around 10V with the load but as soon as I covered the panel the voltage dropped to zero.

    Can panels have a capacitance?
  5. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    The panels are most efficient at converting visible wavelengths, but will also convert wavelengths not in this range. Your cardboard may be 'see thru' at wavelengths other than the visible spectrum.
  6. shortbus

    AAC Fanatic!

    Sep 30, 2009
    Spinnaker, don't mean to hijack your thread, but have been wondering why they don't/can't make a panel that converts ultraviolet or infrared to electric? Even on cloudy days or at night there is still a large amount of that spectrum available.

    We now return you to your previous thread. :)
  7. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    No problem. My guess that it is possible but there is just not enough energy in those wave lengths to make it worth it.
    shortbus likes this.