Fronius Primo vs SMA Sunny Boy AV-41 side by side. Making the right solar energy system choice isn’t easy. With many perspectives telling you what’s best, ask yourself “the best of what?” Best features? Best guarantee? Best performance? Make a decision based on what’s important to you.


Make: Fronius vs SMA.

Model: Primo vs Sunny Boy AV-41.

Variants: 3 / 4 / 5 kW.

Supply: Single-phase.


The following content for the Fronius Primo vs SMA Sunny Boy AV-41 should be used as a guide only. Individual circumstances and compatibilities should always be taken into account when selecting the right solar inverter for any given installation. This content has been built using the Solar Review Inverter Assessment Criteria 2.0 or above based on available product specifications at the time of writing. 


Design is what defines a particular solar inverters ability to meet end-user expectation from modern appeal, future integrations and versatile installation locations.


Primo Design; VERY GOOD
  • AC Coupled battery compatibility.
  • Released 2013.
  • Fan Cooled.
  • Plus X Award "High Quality, Functionality" and "Best Product of 2013".
  • TÜV Reihnland certified.
  • Inspiring.
  • IP 65.


  • AC Coupled battery compatibility.
  • Released 2019.
  • Fanless.
  • Global Solar + Energy Storage “Solar PV Inverter of the Year” award 2019.
  • TÜV Reihnland certified.
  • Inspiring.
  • IP 65.


As the heart of your new self sufficient power supply, the features of an inverter define the opportunity for diverse interaction, variable installation design methods and defined asset management opportunities.


Primo Features; SUPERIOR
  • 2 x MPPTs.
  • LCD Graphic & basic LED interface (no internet required).
  • WiFi & Ethernet inbuilt.
  • NO manufacturer supplied module-level optimisation options.
  • Manufacturer supplied module-level rapid shutdown options.
  • Manufacturer supplied expanded monitoring options.
  • Fronius Dynamic Peak manager.
  • Remote access support limited to firmware updates (max).


  • 2 x MPPTs.
  • Multifunction LED & local app connectivity (no internet required).
  • WiFi & Ethernet inbuilt.
  • Manufacturer supplied module-level optimisation options.
  • Manufacturer supplied module-level rapid shutdown options.
  • Manufacturer supplied expanded monitoring options.
  • SMA Shadefix
  • Remote access operational parameter adjustments (max).


Performance in more ways than just efficiency alone. How does a solar inverter perform within its intended environment and in adverse conditions? The key specifications not often at first thought.


Primo Performance; VERY GOOD
  • 97.1% Weighted efficiency.
  • Min temperature range -40°C.
  • Max temperature range +55°C.
  • Temperature derating point 40°C.
  • Weight 21.5kg.
  • Noise emission max 65 dB (A).


SB AV-41 Performance; SUPERIOR
  • 96.5% Weighted efficiency.
  • Min temperature range -25°C.
  • Max temperature range +60°C.
  • Temperature derating point 50°C.
  • Weight 16kg.
  • Noise emission max 25 dB (A).


Manufacturer guarantees are interesting when selecting an inverter technology. More commonly is a complimentary extension to base guarantee options in recent years. As guarantee obligations can often be shielded by installer incompetence, should a manufacturer define an adequately trained installer network with a complimentary warranty extension (added end-user benefit), such guarantee has been considered as a base warranty more likely of adhering manufacturer installation specifications.


Primo Gurantee; OUTSTANDING
  • 10-year parts warranty.*
  • 10-year service warranty.*
  • *Authorised installer network with additional end-user benefits.


SB AV-41 Guarantee; SUPERIOR
  • 10-year parts warranty.*
  • 5-year service warranty.
  • *Authorised installer network with additional end-user benefits.


In a modern world, software is how you interact with your self generated power supply. More than just a monitoring portal, inverter software is evolving to become the entire energy management protocol as the new standard.


Primo Software; SUPERIOR
  • Fronius Solar.web
  • iOS & Android app.
  • Alerts & fault diagnosis.
  • n/a
  • Consumption monitoring options


SB AV-41 Software; ELITE
  • EnnexOS (2020).
  • iOS & Android app.
  • Alerts & fault diagnosis.
  • Module-level monitoring options.
  • Consumption monitoring options.



Primo Overall; SUPERIOR
  • Design 3.5
  • Features 4.1
  • Performance 3.6
  • Guarantee 5.0
  • Software 4.0


SB AV-41 Overall; ELITE
  • Design 4.0
  • Features 4.8
  • Performance 4.1
  • Guarantee 4.2
  • Software 4.5


*AVG references industry average specifications.

[ 4.8 - 5 ] The pinnacle of certified specification.
[ 4.3 - 4.7 ] A rare calibre of technology produced by the industry elite.
[ 3.8 - 4.2 ] Specifications which are exceedingly superior to that of the industry average.
Very Good
[ 3.3 - 3.7 ] Advanced technology against the industry average.
[ 2.8 - 3.2 ] Better than the industry average is that of which strives a portion better.
[ 2.3 - 2.7 ] A score within this bracket is considered the industry average specification.
[ 1.8 - 2.2 ] Considered below the industry mainstream average.
[ 1.3 - 1.7 ] There's better, there's also worse.
[ 0.8 - 1.2 ] Far below the modern industry average.
[ 0.3 - 0.7 ] Possesses specifications which are absent or unverified by a certified testing institute.
[ 0 - 0.2 ] Unlikely for technology manufactured in the modern era.


How was the score for the Fonius Primo vs SMA Sunny Boy AV-41 solar inverters calculated? By using the Solar Review Inverter Assessment Criteria V2.4 >

This article was originally published February 29, 2019.


To reflect evolving criteria this content has been updated over time.


Revision dates:

  • April 29, 2020

How does the entire current range of Fronius and SMA solar inverters compare against each other?


  1. There’s a couple of things in this comparison i wasn’t aware of, such as the higher operating temperature of the Sunny Boy inverter, thanks for pointing that out. In regards to software (monitoring), do you have ENEX OS already in the US? In Australia, we are still on the standard sunny portal. Can definitely agree on the noise, comparing the DB, you don’t hear anything on the SMA inverter but on hot days, the Fronius is quite noisy.

    • The data migration will take time globally. Options to register a system under ennexOS are available through Sunny Portal however, it’s not quite there yet. The Fronius Primo has been a good inverter for some time, it does appear though, overall it is now languishing behind an evolved residential inverter offering in the last few years.

  2. In every section the chinese SMA is better. Doubt. Pity, I cannot find the crap solar post where the old german and chinese version compared by inside. I dont think in this case SMA is better in any scenario, also they plan to turn their head back to Germany and shut down chinese manufacturing. What a well decission, go out then turn back. I think this review is totally one-sided.

    • You’re entitled to your perspective, no question. All Solar Review does is identify the best specifications commercially available and scales the scoring accordingly to what is best down to average and then below average Rest assured there is no bias in the Solar Review criteria, the specifications are what they are, irrelevant of manufacturing origin. Is the Fronius’s temperature derating at 40°C better than the SMA 50°C? Fact is there is better still available on the market. Is the Fronius Primo’s noise emission at 65 dB (A) better than SMA’s <25 dB (A)? Does Fronius have a Fronius supplied module-level optimisation option? How does the Fronius Solar.web monitoring system compare to the SMA's Intersolar award-winning ennoxOS energy management software? Where the Fronius Primo range is superior to the SMA Sunny Boy AV-40 range is negative operating temperatures -40°C compared to -25°C. These are just a few examples, the scoring is relative to the varified product specifications in each field. Defining technology by region of manufacture alone in rapidly advancing technologies is obsolete and narrow-minded in a modern world. The beauty is today, prospective solar shoppers have the luxury of choice and the Fronius Primo is still a very good inverter option in every sense and has been for a good portion of time.

  3. I had a fronius for a couple of months and the fan noise was absolutely horrendous so i switched to a sunny boy and not only do i have a quiet back yard again but this sunny boy inverter is generating more power. I have an app on my phone to see whats happening. The Fronius belongs in an industrial setting not in suburbia. Also i cant stand that Fronius have 2 fans, one goes off at 2000kwh but when its generating over 3000kwh it uses the 2nd fan, its unbearable and the fans give it a real cheap feel. Whereas sunny boy has a heat sink. I luv it. So i totally agree with this review cause ive lived through it.

  4. Is there an update to this review? (April 2020) I’m in Australia and we installed a 6.5kW system with an SMA 5.0 inverter about 3 years ago. We have now sold this house and are moving to a new one so I am currently in the process of buying a similar 6.6kW system for it. All the installers I’ve spoken with now say that Fronius is better than the SMA, better performance, better value, better after sales service and so on.

    Our SMA had constant niggling problems with its wifi UI, and late last year SMA finally changed it over under warranty, but the same problems persist.

    One thing that is really good about the SMA is their Sunny Places monitoring software which allows you to compare your systems performance with other similar installations in the region (or anywhere for that matter). Im not aware that you can do that with the Fronius.

    For more complex system management Sunny Portal is also pretty good giving the user access to quite a few system settings, system logbook, etc.

    The local installers all seem to sing from the same hymn sheet – that SMA lost their way when they went for Chinese manufacture a few years back, and that now they are taking it back to Germany, but are still behind.

    Until I read this Feb 2019 review I was just about ready to accept the Fronius as a given.

    An update to this comparison would be very handy.

    • Isn’t it interesting the word “better” our view is “the best of what?”. Installers and alternative platforms often have perspectives aligned with a sales bias. Some would say it’s easier to sell a European made product over a Chinese made product of similar price to the unknowing buyer. The aim of Solar Review is to draw a line in the sand surrounding product specifications and where they are positioned against the industries best-known specifications. Disregarding manufacturing origins (as it cannot be measured) will assist in product clarity ensuring trusted independent testing institutes verify the specifications. Besides, many technologies around the world are simply assembled in certain locations comprised of various international components. The manufacturer, no matter the assembly locations, define product quality.

      Let’s get this comparison up to date as there have been some changes on the Fronius front in the criteria of Guarantees.

    • Yeah I just stumbled upon this review too. My off-grid VRLA batteries setup in Australia need replacing years ahead of when they should. Two separate off grid experts have independently inspected the system and said that the SMA inverters installed on default settings have poorly handled the VRLA batteries and cut their lifespan. On top of that I’ve personally witnessed pretty ordinary tech support on a number of occasions from SMA. It’s most amusing seeing an SMA accredited installer get the shits with them! They did say they were great 10 years ago, but both off grid experts have recommended ditching *all* the SMAs in order to get the system working properly. Fronius and Selectronic were among several recommended alternatives. One guy has a stack of used Sunny Boys and Sunny Islands in the back of his workshop gathering dust.

  5. The Fronius 10-year Parts & Labour warranty is only provided by ‘Fronius Service Partner Plus’ solar companies. The majority of solar companies are not FSP+ so their Fronius inverters only come with the standard 5+5 year warranty (labour only covered for the first 5 years)

    • Precisely, and the reason why Fronius’s guarantee ranks as it does in this instance. End-users should be encouraged to purchase solar equipment through adequately trained, manufacturer aligned installers for greater warranty assurance. This is referred to as an end-user benefit. An outstanding initiative on behalf of Fronius ensuring a comprehensive warranty with installations more likely to meet manufacture specifications through additional training.


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