Solar Manufacturer Fronius Celebrating 80th Anniversary

From modest origins in a small Austrian workshop repairing radios in 1945, Fronius has grown into a solar innovation leader. In 2025, the company celebrates 80 years since it was founded.

In June 1945, Günter Fronius – an electrical engineer – started a service repairing radios and electrical appliances. An inventive type, it wasn’t long before he developed a car battery charger, which were still uncommon at the time.  Mr. Fronius became a very busy man but continued expanding his business, branching out into welding transformers 5 years after kicking off operations. Welding technologies are still a core focus of Fronius today.

Fronius Steps Into Solar

The company continued to grow and in 1992 launched its solar division. The Fronius Sunrise Midi grid connect inverter was released a few years later, which was a 1.5kW unit weighing in at approximately 25kg. Next up, and somewhat of a misstep initially, was the launch of IG inverter range in 2001. Early models had issues such as communication errors, grid problems, overheating, and internal faults.

Fronius learned from the early IG inverter situation and pushed on. When the company launched the SnapINverter range in 2014 that featured an innovative simple mounting system, the accolades soon followed. This range served the company and its customers very well, but SnapINverters were phased out last year.

SnapINverters have been replaced with the Symo and Primo Gen24 series of inverters. Among new features and improvements, the Gen24 series addresses a common gripe about its predecessor – fan noise. SnapINverters get quite loud when the inverter is working hard, such as on very hot days. Most inverters don’t have a fan and heatsink (active cooling), instead relying on convection (passive cooling) with just a heatsink. But the fan helps keep the unit working at optimum efficiency, and a cooler solar inverter can mean a longer service life. While the Gen24 inverters have a large fan, they are much quieter.

Fronius solar inverter evolution – the Midi Sunrise, IG Plus, Primo SnapINverter and Gen24

Fronius inverter reviews here on SolarQuotes from Australian customers have averaged 4.8 stars from an eye-popping 8,819 ratings at the time of writing, and 4.9 stars in the last 12 months (761 ratings). In the SolarQuotes Installers’ Choice Awards for the best solar inverters in 2025, Fronius took out top spot for the 5th year running.

Beyond Solar Inverters

Aside from solar inverters, Fronius made its first move into solar energy storage in 2015 with the Fronius Solar Battery. While discontinued in 2023, in early March 2025 the company launched the Fronius Reserva home battery that will be available in Australia at some point.

Fronius also produces the Ohmpilot. Released in 2017, the Ohmpilot is a PV diverter designed to use surplus solar energy to heat water and power other resistive loads. Added to that is the company’s very good (but pricey¹) Wattpilot EV charger, which was launched in May 2021. The Wattpilot took out gold in SQ’s Installers Choice Awards for the best EV chargers in 2025.

Still A Family-Run Business

Günter Fronius handed over the reins of the company to Brigitte Strauß and Klaus Fronius in 1980. Granddaughter of the company founder, Elisabeth Engelbrechtsmüller-Strauß, took over management of the company from her mother and uncle in 2012 and is the CEO of Fronius today. Reflecting on her grandfather’s legacy, Ms. Engelbrechtsmüller-Strauß said:

“If you look at the conditions at the time, our beginnings were characterized by innovation, daring and solidarity. The scarce resources awakened my grandfather’s inventive spirit and encouraged him to make the best possible use of what was available, to make it repairable and to make it affordable for a broad section of the population.”

Commenting on the challenges facing the firm in more recent times from competition and various upheavals around the world that resulted in layoffs at the company:

“We are passionate about renewable energies and are consistently adhering to our vision of 24 hours of sun. The solar market has been and continues to be characterized by ups and downs, and the effects of the recent crisis are still clearly noticeable,” stated Ms. Engelbrechtsmüller-Strauß. “But our 80-year history has taught us that even in challenging times we do not give up, but – on the contrary – emerge stronger.”