mono vs poly crysstaline panels

706jim
706jim Solar Expert Posts: 514 ✭✭✭✭
Poly seems to be cheaper than mono. What's the difference? Looking to buy enough panels for approx. 1kw.
Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 30th year.

Comments

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Mono panels are sometimes a bit more efficient (more watts per sq.ft.) than poly, which can be a factor if space is tight and you want the most power from available space.

    I think there used to be other differences, but these days I'd go with cheaper poly unless you're really cramped for space (eg. marine/rv application).
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Mono are sliced from ingots (basically a single big crystal), while poly crystalline, are kind of the chuck and formed lunch meat type, then sliced...lol. There is also a molten type poly done by drawing a molten silicon between 2 threads, This uses a less energy, not sure if it's still done, it was the last value of the evergreen solar company and was valuable enough for the company to be sold rather than going bankrupt. You can skip down to the second article here;

    https://en.wikipedia.org/wiki/Polycrystalline_silicon

    They should pretty much stable and identical once made into panels, but mono tend to have higher efficiency (which should be taken into account in their rating)
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • 706jim
    706jim Solar Expert Posts: 514 ✭✭✭✭
    Thanks for the info. I plan on placing this group of panels on the ground and I have a ton of space available. So poly it will be.
    Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 30th year.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    edited April 2017 #5
    While I have some mono made in 1980 that still produce nicely. The Evergreen panels I bought in 05 are still working, though I sold them and can't tell you if they have had noticeable reduction in production. They are on a PWM charge controller, so I don't know that they would even notice if they had a voltage drop. The new owners are still friends :) .
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.