Technological pioneer and groundbreaking products
REFU Elektronik develops and manufactures inverter and energy storage solutions for residential and commercial use. The focus is on synergistic components for stationary energy solutions that serve as a common platform for implementing the energy transition.
Technological pioneer and groundbreaking products
REFU Elektronik develops and manufactures inverter and energy storage solutions for residential and commercial use. The focus is on synergistic components for stationary energy solutions that serve as a common platform for implementing the energy transition.
In addition to high-performance hardware, REFU also offers software solutions for the photovoltaic sector that are developed and hosted in Germany – for optimal interaction between energy generation, storage and management. By combining expertise in high-performance electronics, we create economical, efficient and environmentally conscious technologies. The key to success lies in combining expertise in controllable power electronics with customer-specific design and flexible manufacturing.
Since 1965: Pioneering spirit made in Germany
For almost two decades, the name REFU Elektronik has been inextricably linked with the energy transition. Since 2007, the red inverters can be found all over the world. But the history of REFU goes back even further.
1965 to 1997: From beginnings, world firsts and new beginnings
REFU never stood still. Founded in Stuttgart in 1965 as a company for controllable frequency converters, it quickly developed into a hidden champion. The frequency converters were in demand and were constantly being further developed. In 1982, by which time REFU had moved to Metzingen, a true world first was achieved. The world’s first digital frequency converter celebrated its premiere. In what was then a largely analogue world, it was a genuine world first and an innovation made in Germany. In 1997, REFU finally presented its first solar inverter. This was an OEM solution (short for Original Equipment Manufacturer solution) and impressed with its performance values.
Establishment of REFU Elektronik
1965
Aquisition by the PRETTL Group
2004
Product launch REFUsol 100K, 500K, 630K
2008
New product line REFUsol, Gen II REFUsol 10-15K
2009
Launch of new product line: REFUsol 8K, 333K, 24K-UL
2011
Acquisition by Advanced Energy
2013
Product launch PV-Inverter Power String 40/46K
2014
Reacquisition by the PRETTL Group
2015
Establishment of REFU Hungary and start of R&D
2020
REFUsol 20K-50K market launch
2021
Acquisition of REFU Storage Systems by PRAMAC
2023
New generation of product families REFUsol 20K-350K
2024
New product ranges and hybrid inverters.
2025
REFUsol: a new red standard
It was still a long way from the first OEM inverter to the first proprietary solar inverter. So, for the next few years, the company limited itself to developing joint products for partners such as SIEMENS. Numerous devices from this generation are still in use today. These relationships led to the development of a proprietary product.
In 2007, a new name appeared on the solar market for the first time: REFUsol. ‘Sol’, short for solar and Spanish for sun, shone proudly over the main location in Metzingen. Technically, the first REFUsol inverter was something special. It easily caught up with the other devices available on the market, both in terms of performance and durability. The next generation of REFUsol, on the other hand, became a benchmark. A benchmark made in Germany.
Awards and new products
Generation II of REFUsol was a complete success. The inverter set new standards, including in design. Red became the new colour of the energy transition. Soon, red REFU inverters were lining many solar installations. Not only in Germany and Europe, but worldwide.
REFU devices won numerous prestigious awards. They won the Photon Labs Efficiency Award several times, even in succession (2007-2010). In addition, they won the prestigious Innovator Award from 2011 to 2013. At the time, this was the largest audience award in the German economy. In addition, the company won the Red Dot Design Award (2013) and the Solar+ Power Award (2017), among others.
From 333K to 350K – breaking through barriers
For a long time, REFU Elektronik focused on the smaller power classes, ranging from 3K to 40K. But then the pioneering spirit of the developers struck once again! The REFUsol 333K was developed, launched on the market as a milestone in German engineering and remained the benchmark in this power class for a long time.
Other competitors also developed inverters with higher power classes, but were unable to surpass this power class.
Until 2024. Ultimately, it was REFU Elektronik itself that was able to surpass its own benchmark. With REFUsol 350K, one of the most powerful inverters to date was introduced. Since then, REFUsol 350K has impressed customers worldwide and is already powering numerous large-scale installations.
New product classes for 2025/2026
At Intersolar 2025, REFU Elektronik presented two new product classes: REFUhyb and REFUbat. REFUhyb marks the company’s entry into the hybrid inverter market.
In addition, REFUbat will offer a home energy storage solution from 2026 onwards.
REFU Team
At REFU, we believe great solutions come from great people. Our diverse team spans across Germany, Spain, Hungary – and reaches even further through close collaboration with our colleagues in India. With expertise rooted in different cultures, disciplines, and backgrounds, we work together every day to deliver smarter, more sustainable energy solutions worldwide.
Our locations
From Pfullingen to the world
With over 400,000 inverters installed in more than 25 countries, REFU is actively contributing to the global energy transition. REFUsol inverters are particularly widespread in the core markets of Europe, Asia and India – reliable in operation and efficient in energy yield.
Headquarters – Pfullingen, Germany
REFU manages its global activities and strategic planning from Pfullingen. With decades of experience in power electronics, the Pfullingen site plays a key role in shaping innovations, ensuring quality and driving the company’s long-term vision.
Development site – Seville, Spain
REFU operates a modern development centre in Seville. The facility is dedicated to the further development of the company’s energy management solutions, inverter technologies and digital platforms.
REFU Hungary – Érd, Hungary
In Érd, REFU Hungary operates a 12,000 square metre state-of-the-art production facility with excellent logistical connections, supplying partners throughout Europe and beyond.
Our goals & values
Our mission
We develop innovative energy solutions that contribute to the global energy transition.
Our Vision
Clean, smart energy for everyone – global, efficient, sustainable.
Our goal
We stand for German reliability, smart innovation, and sustainable energy for the future.
Jens Mollitor
CEO of REFU
When we look at our history, I think that we have always been pioneers. And also had the courage to pursue ideas – even those that were too far ahead of their time. Did all these ideas work? No, of course not, but every idea has inspired us.
REFU is an important part of the history of inverters. Founded in Stuttgart in 1965, our red PV inverters have found their way around the world and are represented on every continent. I have been managing the fortunes of REFU since November 2024. The big goal in 2025 was to realign ourselves on the product side. We have expanded our product portfolio. Expanded by performance, expanded by quality.
We have achieved our goals because we trust in what has characterised REFU since its foundation: creativity and determination. We have also formed new partnerships and are now stronger for the coming years.
Let’s shape the future together!
Gerhard Heilemann
CEO of PRETTL
With my background in electrical engineerin and many years of experience in marketing and sales, I see it as my mission to help build strong, future-oriented brands within PRETTL Ventures.
I’m particularly excited to contribute to the development of sustainable products and green energy solutions. This is where my passion meets PRETTL Ventures’ vision with REFU at the core of our vision for the energy transition.
Part of PRETTL
Since 2004, REFU Elektronik has been part of the internationally successful PRETTL Group – a family-run group of companies with over 70 years of experience and more than 10,000 employees in over 40 locations worldwide.
Integration into the PRETTL structure has not only enabled REFU Elektronik to grow internationally, but has also laid the foundation for continuous technological innovation in the field of photovoltaics and energy management. Combined with the PRETTL Group’s innovative strength and commitment to sustainability, REFU is ideally positioned to actively shape the energy transition worldwide.
