question

offroadflow avatar image
offroadflow asked

Vast difference of solar input power and inverter output power



screenshot-20220217154921.png

3x 48/5000 Multi

2x 250/100 MPPT

Venus GX

Batteries in IDLE mode.

No DC consumption at all (off grid installation).

Solar in/power out has a difference of about 800W.

This can't be right..?

A few hundred watts in energy loss OK, but 800??? This gap is constant, even getting bigger with more power out (through)..

MPPT Controllerspower meter
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2 Answers
nickdb avatar image
nickdb answered ·

Depending on the type of load, inverted resistive loads lose about 10% at the most efficient, other load types lose more.

Reporting isn't always in sync, at 13% that is about right for efficiency.

It's basic physics.


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seb71 avatar image
seb71 answered ·

Maximum efficency of your inverters is about 95%. The efficiency drops at higher loads.

Also each inverter draws 20W or so for self-consumption. The MPPTs have some small power draw. Venus GX probably takes 5W or so. Cable/wire loses can be high, too, if the wires are undersized. After you take these out, you are left with about 89% overall efficiency. Not great, not terrible. :)

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