Shade and its effects on solar panels

Replies

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  Ankita Katdare

  Interesting topic. It will be great if you can explain it a bit further as direct explanation of both the points is available on various websites.
  I am reading that even partial shading is bad for solar power systems.
  
  Tagging a few people #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# here.
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  Siddhant Mukherjee

  The photovoltaic cell output is directly dependant on the light intensity falling on it. Shade will adversely affect the performance of a solar panel. This is because the radiant intensity(power/unit area) will decrease due to shade. But for such conditions where sunlight is not very abundant, a different type of light absorbent glass is used, which is textured so that light entering the glass does total internal reflection inside and is almost completely absorbed. So, it somewhat helps in increasing the power output. In areas which are more shady such glass can be used to enhance the power of solar cells.
  
  The following link shows a type of textured glass.
  
  #-Link-Snipped-#
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  Ramani Aswath

  Photo voltaic effect exists at all light levels. The output depends on the incoming radiation.
  Depending on the amount of light (even under hard or soft shade) from the portion of the sky seen by the panel the output current and to some extent voltage will vary.
  I am currently experimenting with a panel associated with a rechargeable lantern designed by an Australian Greenplanet organization
  #-Link-Snipped-#
  
  The panel is lying horizontal (not the best position but being tested by me) on the first floor parapet wall. To the east is a multistory building . The panel does not see the sun till 9 AM. It starts charging the battery at the lowest level 20% current well before ( even though it is in full shade of the building on the East) 9 AM. It is receiving the back ground skylight. You can see the increase in charging if a large white cloud illuminated by the as yet invisible sun behind the building passes overhead.
  
  The new generation Lithium Ferro Phosphate battery is said to have a five year life. It is supposed to charge fully on a full sunny day to deliver 10 hours continuous burning of the LED lamp at normal illumination. It is now one month since I started the trial. The lamp works for ten hours every night. There is still some charge left in the battery. It gets fully charged before 12 noon even on slightly cloudy days at the Bangalore latitude of 13 degree North.
  
  I am impressed by the lamp. The higher end version of this can also charge cell phones.
  
  The products from this organization can be seen here:
  #-Link-Snipped-#
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  Akhilesh Garud

  I wanted to know what will happen if both the shades occur simultaneously on a solar array? how will they affect the output?
• 

  Ramani Aswath

  akhilesh.garud

  I wanted to know what will happen if both the shades occur simultaneously on a solar array? how will they affect the output?

  I suggest that you go through this article:
  #-Link-Snipped-#
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  Void Runner

  Okay, allow me to answer this one.
  
  Photovoltaic effect is basically current generated due to generation of hole-electron pair in an otherwise static p-n junction. Now assume that you have a solar panel which is composed of many solar cells arranged in series or parallel.
  
  Hard shade effectively "deactivates" certain parts of this array. This means, those parts act as "dead loads" to the circuit, generating only heat. This can potentially be damaging to the array (note: deactivation of certain parts of an array --> remaining circuit goes into overdrive to maintain current/voltage output). Soft shade is a bit safer, it implies that the devices are still working but less efficiently, which means the output of the panel is affected anyway, but chances of damage are less.
  
  There are ultra-technical explanations for this, but the above will be fine for this level I think 😀
  
  Source: Engineering Physics/Electronics major 😀
• 

  Jeffrey Arulraj

  Photo light
  Volt Potential
  
  Photo voltaic => Potential due to light.
  
  light intensity is amount of light per area.
  
  Light intensity is inversely proportional to shade. (universal fact)
  
  So if a device works on light it can't be in shade.