Misleading information from a supposed reputable? company

mcgivormcgivor Posts: 2,211Solar Expert ✭✭✭✭✭
This video demonstrates how misleading information can influence people's opinions and ultimately decisions on what is the best controller. There is some information which is valid, the MPPT controller will have an advantage over PWM with a 24V nominal panel, that's because the PWM is not designed to use such a panel, it would need a 12V nominal panel so as not to be so grossly over voltaged, if a 12V nominal  panel were used with the PWM, the difference in results would be less dramatic. The comparison should use compatible panels as described above, but also introduce temperature, the actual deciding factor, as the temperature drops the voltage increases which is where MPPT has its advantages, in a tropical location where temperatures are consistently high ~30°C or above, not so much. Judging from the comments in general many were wowed by the apples to oranges comparison, probably due to ignorance, they merely believe what they saw assuming it was gospel. Ignorance is not stupidity, but believing everything seen on YouTube is factual, is getting pretty close. 

1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

Comments

  • BB.BB. Posts: 27,902Super Moderators, Administrators admin
    Yes, improperly/poorly designed systems may not work "optimally". Install those systems on a 24 volt battery bank--And run the same test. Much less difference.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave AngeliniDave Angelini Posts: 4,021Solar Expert ✭✭✭✭
    But it is Amy and she is happy to sell you solar ;)
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PhotowhitPhotowhit Posts: 4,705Solar Expert ✭✭✭✭
    It's actually hard to explain to someone, you have a bunch of variables and you are speaking in terms most don't use everyday.

    I suspect everyone here has had people just go blank when you are explaining the difference. 
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • BB.BB. Posts: 27,902Super Moderators, Administrators admin
    Yea... It is a good example of what an MPPT and PWM charge controller can do... But there is a whole bunch of stuff behind the scenes that go into designing and operating an off grid (or even grid tie) solar power system. The demo is "not enough" knowledge, by itself, to design a system (and I don't think that they really were saying it was).

    This is why engineers are no fun at parties.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ThomThom Posts: 184Solar Expert ✭✭✭
    I bought many things from them. We’re very helpfull . You can’t judge a store by a utube video. 
    Off grid since 1984. 430w of panel, 300w suresine , 4 gc batteries 12v system, Rogue mpt3024 charge controller , air breeze windmill, Mikita 2400w generator
  • mcgivormcgivor Posts: 2,211Solar Expert ✭✭✭✭✭
    The video was probably not intentionally misleading but rather potentially misleading, there is no judgment of the store on my behalf, just pointing out how easy it is to create an allusion (not illusion ), even with good intent. A side by side comparison  with 12V nominal modules,  in series for MPPT,  an equal count in parallel for PWM, then cool the panels with water to demonstrate the effects module temperature has on voltage and how MPPT is benificial, emphasizing that the colder they are, the greater the difference in production would be..
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 

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