Fronius Primo vs SMA Sunny Boy


I’ve received a number of quotes and narrowed it right down. My only decision now is whether to go with the Fronius Primo or SMA Sunny Boy inverter - there’s only a $50 difference. Depending on who you talk to you get mixed answers. On some reviews SMA is the overall winner however other reviews state Fronius is number 1.

Which is better? Why? Is it just personal/installer preference. Hopefully I can be sold on one with some pro help


Hi @BJDCC, welcome back.

It’s a really tough choice these days, or easy choice - in that you should be really confident on either of them. Toss a coin! See more here:

Thanks Marty

Can you shed some light on the Fronius Primo 5.0-1 Aus vs Fronius Primo 5.0-1? Looking at the specs I see the ac nominal output is 4,600w and 5,000w. But are they both still 5kW inverters? Is one designed for Aus and another international?


Yeah the only difference is that AC output. It’s just a hard setting that they’ve put in place for some Australian electrical distributors that only allow a max 4.6kW output.

Your solar company should be able to guide as to what the situation is in your area, and which modal is suitable.

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Can the Aus version still support a 6.6kW system or is restricted to the 6.1kW. I can’t seem to find a clear answer :man_facepalming:


Yes both versions have the same solar DC input voltage specifications. The only issue might be that due to the Aus regulations, you cannot oversize the solar more the 133%. This means if the inverter is limited to 4.6kW, then the maximum solar array size allowed is 6.1kW (as opposed to a 5kW inverter which has a 6.6kW limit).

What size is the inverter. Do you require rapid shutdown and do you want backup AC power during outage?