Boasting many admirers due to good track record in the field, the Fronius Primo is purpose-built for single-phase power supplies. A remarkable design now has many competitors vying for your attention as the world becomes less obsessed with manufacturing origins.

.Make and model:  Fronius Primo.

Variants: 3 / 4 / 5 / 6 / 8.2.

Guarantee, Software.

Noise emission, Design.

CONTENTS - The information you need, fast!

Why the admirers? Quality hardware built by a company with a reputable track-record in manufacturing DC appliances for over 80-years. Proving a superior design, many of the critical elements which make the Fronius Primo solar inverter have succeeded for the best part of a decade.

A beautiful sentiment to proven technology, but a lot has changed as solar energy takes the main stage becoming a key feature in modern residential energy supplies. Therefore, how does the Fronius Primo compare against today’s best-known inverter specification?


Internal cooling is fan regulated ramping up to a max 65 dB (A) and considered a likely point of failure. The Fronius Primo remains a worthy candidate for reliable outdoor installation with a robust IP65 dust & water rating. Battery compatibility is available via an AC coupled, or a compatible DC coupled battery such as the SolarWatt Matrix.


Primo Design; VERY GOOD
  • AC Coupled battery compatibility.
  • No change for the last 5-years.
  • Fan Cooled.
  • Major internationally recognised award.
  • TÜV Reihnland certified.
  • Standard
  • IP 65.


Features for greater installation flexibility include; WiFi and Ethernet communication, inbuilt DC isolator, Fronius supplied rapid shut down capabilities with the Fronius Rapid Shutdown Box (if required) and in-depth monitoring insight with additional Fronius devices such as the Fronius Smart Meter. Shadow management is enhanced by more than just dual MPPT array inputs with Fronius’s Dynamic Peak Manager onboard. Additional product support is available from installers to end-users with remote firmware updates possible, plus advanced monitoring data access.

With the technology evolution of inverter information access from almost anywhere, a multifunction LED interface is the new standard of interpreting essential operation locally. LCD graphic interfaces are a common point of failure within inverter design and often expensive to repair. For those seeking module-level monitoring or optimisation capabilities, the Fronius Primo range has no manufacturer-supplied option. To support such a feature a 3rd party device such as Tigo is required.


Primo Features; SUPERIOR.
  • 2 MPPT.
  • LCD graphic interface.
  • WiFi & Ethernet inbuilt.
  • No manufacturer supplied module-level optimisation options.
  • Manufacturer supplied module-level rapid shutdown options.
  • Manufacturer supplied expanded monitoring options.
  • Nominated shadow management protocol onboard.
  • Remote access firmware updates.


Fronius Primo inverters perform better in colder climates. The operating temperature range is outstanding for below-freezing conditions down to -40°C. For areas subject to constant heat the Fronius Primo’s upward temperature range is less than ideal, limited to only 55°C (131°F), derating from the 97% efficiency after 40°C (104°F). Weight is a little excessive at 21.5kg, almost 10kg heavier than leading inverter weight specifications.

The maximum noise emission from the Fronius Primo range is 65 dB(A). Excessive in comparison to a new expected average of 25 dB(A) or less. Even though essential performance traits lag some of the best known, the Fronius Primo range provides VERY GOOD performance criteria.


Primo Performance; VERY GOOD.
  • 97% European weighted efficiency.
  • Min temperature range -40°C (-40°F).
  • Max temperature range of +60°C (140°F).
  • Temperature derating 40°C (104°F).
  • Weight 21.5 kg (47.3lbs).
  • Noise emission max 65 dB (A).


The base Fronius Primo inverter guarantee is a 5-year parts and labour warranty. However, when purchasing through selected Fronius partners, end-users can enjoy a solid 10-year warranty upon redemption after installation.

An approach which provides greater assurance that the product is installed to manufacturer specifications and the warranty has worth. Offering such, end-users can be assured one of the most reliable warranties available. This recent warranty program has skyrocketed Fronius to the pinnacle of the Solar Review Guarantee Inverter Assessment Criteria for OUTSTANDING guarantee assurance.


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

*Purchasing the Fronius Galvo through a Fronius authorised installer facilitates a comprehensive 10-year manufacturer parts & service warranty.


A cut above most other manufacturer supplied monitoring options. See the full Fronius Solar.web monitoring software review for more insight > (Coming Soon).


Primo Software; SUPERIOR.
  • Fronius Solar.web
  • iOS & Android app.
  • Alerts & fault diagnosis.


The Fronius Primo solar inverter is a proven single-phase solar inverter solution where a successful design hasn’t need to waiver much within the last decade. As technology has evolved, the once high-spec Fronius Primo is now only somewhere near the top of its class with much of the competition learning from previous design flaws, evolving or better yet, innovating.

The question mark, what will Fronius do next in the single-phase category? It appears as though a stripped-down version of the Fronius Primo GEN24 hybrid is the likely evolution of this SUPERIOR inverter range. Solar inverters are the new brain of the modern energy smart home, and an innovative improvement here would be welcomed by many.


Primo Overall; SUPERIOR
  • Design 3.3
  • Features 4.1
  • Performance 3.7
  • Guarantee 5.0
  • Software 4.0


*AVG references industry average specifications.


How was the score for the Fronius Primo solar inverter calculated? By using the Solar Review Inverter Assessment Criteria V2.5 >

How does the entire current range of Fronius solar inverters compare against each other? Discover now >


  1. I got the fronius symo invertor with the 6kw solar system in October last year, however few days later, I kept getting emails from the solar web advising that there is an error: AC voltage too high
    Please advise


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