Project presentations on the website

Every project supported by Gebert Rüf Stiftung is made accessible with a web presentation that informs about the core data of the project. With this public presentation, the foundation publishes the funding results achieved and contributes to the communication of science to society.


SoHHytec – Solar fuels, the smart way


The project management is responsible for the content of the information provided.

Project data

  • Project no: GRS-078/20 
  • Amount of funding: CHF 150'000 
  • Approved: 29.10.2020 
  • Duration: 06.2021 - 08.2022 
  • Area of activity:  InnoBooster, seit 2018

Project management

Project description

Hydrogen is recognized as a sustainable alternative to conventional fossil fuels. Hydrogen is already widely used as a feedstock and processing component in a multitude of industrial processes (e.g., metalworking, fertilizer, chemicals, electronics, etc.) and its adoption as a fuel for mobility and energy storage is growing. However, there exists no effective on-site clean-hydrogen production system: ~96% of the world’s hydrogen demand is met by transporting fossil-fuel-based hydrogen from centralized steam-reforming facilities. This causes pollution and additional expenses.
SoHHytec SA, together with LRESE at EPFL, has developed the Arb an artificial tree offering a versatile solution to these problems. We use our innovative patented technology based on an integrated photo-electrochemical device. The Arb uses sustainable resources (sunlight and water) to produce highly pure hydrogen, and also co-generates oxygen, electricity, and heat all at the same time and on the same site; with efficiencies of ~70% requiring minimal ground/roof space.
We are providing onsite fuel and power generation systems for industrial (energy, chemical, mobility, oil & gas, steel industries, etc.), residential (rural and urban), and agricultural/farming sectors. Arb saves 15 tonnes of CO2 emissions for each tonne of hydrogen produced and has a potential to reduce emissions by more than 500 million tones/year in the near future.


We have designed, built and operated a first version of our Arb pilot at EPFL, Lausanne campus. During the the Innobooster project, we optimized various components and performed the long-term testing compaign for multiple months. Additionally, the control software of the pilot was extended and optimized to allow for fullly automated operation. The pilot’s flexiblisation i.e. the ability to produce hydrogen, oxygen, electricity and heat in varying ratios as well as ability to produce fuel at 100% capacity even during cloudy or night periods (i.e. hybrid operation) was tested for industry-relevant scenarios. The successful testing over multiple months established the durability and reliability of the system, which was further enhanced with industrialisation plans, to deploy the Arbs for industrial segments.
We also secured our first industrial customer which is a steel processing factory in Switzerland, where we are deploying an ‘Arbs Garden‘ comprising of 5 Arbs (>100 kW). To support this, a system level model for a multi-Arb farm was developed and used to preliminary design the commercial pilot. This virtual multi-Arb pilot will serve as a key design and implementation tool for our future projects.
SoHHytec SA, spin-off from LRESE EPFL, is in the process of concluding collaborations with additional steel manufacturing companies, energy and gas utilities, fueling station developers, oil and gas companies in order to broaden and expedite the introduction of the technology to market. SoHHytec recently closed its seed fundraising round of 2 M USD led by Singapore based VC, in addition to already secured financial support from FIT SEED, Venture Kick and ESA-BIC CH.
Our commercial pilot in Switzerland i.e. the Arb Garden is planned to be followed by commercial pilots around the world—noticeably in the EU, US, and India—targeting the growing market for clean hydrogen generation worldwide, which is estimated at EUR 120 billion.


Persons involved in the project

Co-project leaders
Dr. Saurabh Tembhurne, Project leader from SoHHytec, CEO of SoHHytec SA
Prof. Dr. Sophia Haussener, Project leader from EPFL, Head of LRESE-EPFL

Project members
Dr. Ehsan Rezaei, Scientific collaborator from SoHHytec
Guilherme Armas: Scientific collaborator from LRESE-EPFL
Nathaniel Mutrux: Scientific collaborator from LRESE-EPFL

Last update to this project presentation  18.03.2024