• Filter
  • Time
  • Show
Clear All
new posts

  • Does partial shade impact solar cell

    I have a 130 watt solar cell on the top of my RV. I plan on putting a Thule Box on the roof of the RV also. It will extend part way over about 15% of the solar cell unless I make some drastic changes. In another fourm, I had a member indicate that if any part of the cell was covered the whole solar cell would stop working! I don't believe this is correct. So fact or urban legend?

  • #2
    ANY SHADE, will DRASTICALLY reduce your PV output. You don't just loose 15%, you will loose closer to 80%.

    Shade creates a small high resistance area, that limits the total panel output. SOME panels have small "bypass" diodes in them to help reduce this effect, but with only 1 panel, you will have a severe impact. Sorry.
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister


    • #3
      Yeah, got a tree over the road that's throwing shade onto my panels at around 3pm. It's a winter problem too, with the sun being lower in the sky. Still, not getting a heap of power at 3pm anyways, but I get less now with that darn tree. Let's hope some of the tree's branches don't mysteriously fall off shortly.


      • #4
        Some solar cells have to have full sun light to work. It is best to get all the power you can out of the solar panel. Please try to limit shade during day light hours. A friend of mine once installed solar panels on the only roof available. (north side) he never understood why it would not put out power. We went on his roof with some tools and I took a solar panel and pointed it to the sun. Guess what "Power". I then developed him a stand that worked on the north side of his home so he could get power. Problem solved. Shade happens. Shade reduces and stops the production of electrical power in all situations.