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matthewmiles asked

Do solar panels only provide wattage required by load?

I have two 350 watt 24 volt panels in parallel connected to two 140 amp hour agm batteries through a Victron smart solar 100/30 MPPT. Just put the system together. Main load is a 12 volt 45 watt fridge. In ten days of good sunshine the MPPT unit has never displayed solar power above 269 watts. It’s usually showng Pmax around 160 watts. Batteries don’t drop lower than 12.8 volts at night and quickly get up to 13 volts or more and fridge running fine so all seems good. Will the panels only produce close to their maximum when the load is larger? Thanks

matthewmiles

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seb71 answered ·

Yes.

But you are also limited by that 30A maximum current which your 100/30 charger can output.

Since you are using a 12V battery, this means maximum power output is about 12Vx30A = 360W (slightly higher in practice - up to about 430W or so, because the battery voltage can go higher than 12V; I used the nominal voltage for simplicity).

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matthewmiles avatar image matthewmiles commented ·
Thanks. Maybe I should have chosen the 100/50 unit to get the most out of my panels.. But my load will never be very large - a few LEDs and the fridge is all I need.
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