Some new data to add for step down transformer

imcloud
imcloud Registered Users Posts: 25 ✭✭
Sorry for the double post it wont let me reply to that post anymore for some reason?
Anyway, I received the inverter today and it looks like a stout unit.  Now keep in mind I can not hook a valve to this so these numbers are just
in standby, although I played with the programming and it didnt change the watts at all, and the tech support for the control said the units dont pull much more energy when holding a valve open the valves say they pull 190ma to keep open and it will only have valves open 5 hours a day total ....  

for my tests-  First I plugged the control into a wall outlet, it pulled 10.3 watts from startup to idle.  Then I wired the shunt amp gauge to the inverter and the inverter pulled around 6.6-7.1w at idle with the switch on.  Next I plugged the control into the inverter, and from startup to idle the most is pulled was 18.8w (I watched it for about 20 minutes)...   Does this info help telling me how much battery and panel I will need? ,for 19 h a day it will sit here like it is in the picture at around 17-18w....   so does this mean 18x24=432watts per day?  if so how will this translate to amp hours?  I was told 200w of panel in this area will get me anywhere from 600-750 watts a day, is that accurate?   Thanks again for all your help...






Comments

  • imcloud
    imcloud Registered Users Posts: 25 ✭✭
    Anyone?

  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    edited September 2017 #3
    Say 432 watt-hours/day.  That's about 36 amp hours/day from a 12V battery.    So you want a battery around 140AH (depending on needs for periods of little sun).  More if you have an inverter with losses.

    I am available for custom hardware/firmware development

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    edited September 2017 #4
    Sorry, lost track of the threads
     maybe briefly restate the situation ?  Like if you are @ 432wh @12V what's on the inverter ?
    Powerfab top of pole PV mount | 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 ,

  • imcloud
    imcloud Registered Users Posts: 25 ✭✭
    432 is before the inverter that is the watt gauge after the battery before the inverter...
    so that should be my total losses, correct?
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    If you're reading from a shunt between the battery and the inverter, yes.

    We generally figure about 75% of rated output real world production for clean, properly tilted panels in full sun. That would put your 200w panel at around 150w. To get 600wh/day, you'd need ~4hrs of full sun equivalent, which is reasonable in most locations except in winter. This is an average though. Sunny days may be quite a bit more, gloomy days can be almost nothing.
    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
  • imcloud
    imcloud Registered Users Posts: 25 ✭✭
    So the 2 100ah batteries and 2 100 watt solar panels should be a fair start?  OK< next step what would the best "summer time" angle be to mount the panels at?  and do I just point them at south on my compass?  thanks

  • imcloud
    imcloud Registered Users Posts: 25 ✭✭
    edited September 2017 #8
    the latitude is 42.2695° N  , I came up with 18 degree mount angle for summer months...  does this sound right?

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Point them at solar south - likely close to magnetic south most places. Generally, if changing seasonally, summer would be lat - 15° or 27°, winter would be lat +15° or 57°. That's a generality though. In summer, you get more hours of sun with flatter panels, so it depends a bit on your situation. In your application, flatter may make more sense so you can run the load more on solar and less on battery.
    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