Adding a grid-tie inverter to an off grid system, is it possible?

t0nito
t0nito Registered Users Posts: 5 ✭✭
Hi, at the moment I have a 240W panel connected to a MPPT charger charging a battery that is connected to a 1000W inverter, it is mostly used for lighting at night, the battery never discharges completely so the next day before noon usually the battery is charged completly so the rest of the day it is usually just float charging the battery. I was wondering if I could wire a small grid tie inverter in parallel to the solar panel so I could take advantage of the solar energy while it's just keeping the battery topped off. Would this interfere with the MPPT controller?

So in fewer words the output of the panel connected in parallel to the charge controller and grid-tie inverter simultaneously.

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Two controllers cannot share the same array, or panel in this case, with such a small system, perhaps dumping excess power to heat water would be a better choice, but again it's such a small amount and probably not worth the bother. My opinions others may differ.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • t0nito
    t0nito Registered Users Posts: 5 ✭✭
    Ok, seems like it would take ages to break even anyway grid tie inverters are more expensive than I thought, even those chinese ones, what I was thinking was since most of the day the panel is just maintaining the battery, 200 watts or so of power to the grid would atleast compensate a bit through out the day.