Our vision is to develop the world’s leading standard for green hydrogen solutions – making green energy abundance safely accessible and affordable. For anybody. Anywhere.

Our motivation is an emission-free energy cycle in harmony with nature.

Nature sets our example: energy from the sun, wind, and water are enough for a life in clean energy abundance. And we believe that hydrogen, nature’s very own source of power, is fundamental to humanity’s progress and the fuel of the future.


The inventor of SFEERS, Lars Stenmark (1944–2016), was already a legend within the space industry during his lifetime. Throughout his time as an adjunct professor at the Department of Engineering Sciences at Uppsala, he led the research group at Angström Space Technology Center (ASTC) that specialized in micromechanical components for space applications. He combined his experience with his keen awareness of the climate in order to develop SFEERS. In the process, he became known as the man who “brought space
down to earth.”

The idea of the SFEERS first came to Lars when he was driving through Stockholm on his way to the patent and registration office to submit another patent application. He was so taken by the realization of the invention that he decided to pull over and stop the car. He did so for two reasons: to avoid becoming a traffic hazard and to take some serious notes.

Lucky for us all that he did!


It’s a rocky road to a hydrogen society, but finally we will all get there.

Lars Stenmark

Today, the development of the hydrogen battery is being driven forward by a team of seasoned visionaries at water stuff & sun GmbH. The team has a track record of over 20 years of engineering and managing large hydrogen projects. A strong background in building start-ups complements the extensive expertise in hydrogen technology.

Our Team

The company is managed by Thomas Korn, Alvaro Sousa and Jonas Flädjemark. Since its establishment in December 2016, water stuff & sun GmbH has been based near Munich and works closely together with internationally renowned European research institutions to develop the unique system of the hydrogen battery

Thomas Korn, Chief Executive Officer

Thomas has been an expert on hydrogen technology for over 25 years. After completing his studies in engineering at Munich University of Applied Sciences, he took on the role as a design engineer at BMW Research & Development. There he developed two generations of hydrogen (H2) vehicles with hydrogen combustion engines and started working together with Alvaro for the first time. Starting in 2001, he led the BMW research department for fuel cell technology, before relocating to California in 2006, where he headed the BMW North America H2 vehicle and filling station program.

Thomas then moved to the Austrian start-up Alset and took up the post of vice president of technology and innovation, gaining deep insight into the opportunities and challenges of start-up companies. In 2015, Thomas established the award-winning H2 engine start-up business KEYOU, before founding water stuff & sun and developing the unique technology of SFEERS. As CEO and founder, he is actively shaping the future of hydrogen for our society.

Jonas Flädjemark, Chief Operating Officer

Jonas is a serial inventor and innovator with numerous patents as well as several products succeeding in a variety of markets. It was 1996 when he first heard that the future of fuel lies in hydrogen. But it wasn’t until 2008 that he got the opportunity to build a hydrogen-based race car with students at Halmstad University, where he discovered that the biggest problem with the energy carrier was its storage and distribution.

In his search for a solution, he met Lars Stenmark (1944–2016), decorated scientist and astronautics professor at Uppsala University, who introduced him to his invention, the system of SFEERS. Together they worked on developing the science and business case needed to realize their vision of a green future with SFEERS.

In 2013, fate lent a hand when Thomas exhibited an Aston Martin at Le Mans that had completed the 24-hour Nürburgring race earlier that year, and Jonas presented the SFEERS concept to him. The foundations of water stuff & sun were thus laid, and in 2016, Jonas co-founded the company and has been its chief operating officer since then. Today, everything that could only have been imagined in 1996 is real, and Jonas is one step closer to his dream of driving hydrogen race cars.

Erwin Deutscher, Chief Technology Officer

Erwin looks back on more than 25 years of professional experience in the international automotive industry. After studying mechanical and vehicle engineering, he began his career as a mechanical engineer at Steyr-Daimler-Puch in Graz. There, he went through various stations in the areas of powertrain, vehicle body, interior, and vehicle safety.

With the takeover of Steyr-Puch AG by Magna International Inc., Erwin was able to gain a wide range of expertise in comprehensive product development – from conception, system development, to the entire vehicle. Then his path took him to Eastern Europe and Asia, where he was responsible for several projects in the hundreds of millions euro range in the technical management of the vehicle industry. Erwin has held management positions for more than 20 years.

His professional background, passion for sustainable and safe solutions, and his achievements in the field of development and industrialization have led him to water stuff & sun, where, as chief technology officer, he drives the development of the hydrogen battery for the energy transition.

Alvaro Sousa, Chief Strategy Officer

Passionate hydrogen engineer and car enthusiast, Alvaro started his professional career at BMW Research and Development in Munich after receiving his degree in mechanical engineering in Porto. At BMW, he supported the development of the first demonstration fleet of pre-series vehicles powered with an H2 engine. In this role, he started to work closely with colleague and co-founder-to-be Thomas Korn. After acquiring profound knowledge of H2 storage systems and supporting fundamental research on H2 fuel cells, Alvaro went to California to lead the H2-engine technical team that supported the North American fleet operation of BMW’s first-ever series-produced vehicles with H2 engine propulsion. Upon returning home to Porto, Alvaro became a university lecturer in the field of clean vehicle technologies and engines. He then joined Austrian H2-engine start-up Alset and developed the first hydrogen-based racing car ever produced for Aston Martin. 

In 2015, he co-founded H2-engine start-up KEYOU, which focuses on the development of H2 adaptation kits that convert conventional engines and vehicles into clean mobility products. In 2016, Alvaro co-founded water stuff & sun, where he is chief strategy officer, working on a technology that promises to make not only mobility but the economy greener for the future.

Our Research and Engineering Locations

Immerse yourself in the world of hydrogen technology!

Learn more about the future of energy supply in exciting blog articles and discover current events and news from water stuff & sun!