Formic acid as a hydrogen carrier molecule for an energy storage application for buildings and city districts


Hydrogen will play an important role in supplying electricity and heat to buildings and neighborhoods in the future. One technical challenge is the storage and transport of hydrogen. In this research project, the storage of hydrogen in the form of formic acid by direct electrolysis of water with carbon dioxide will be investigated. The focus is on system integration in urban energy systems, operation with intermittent renewable energy, and continuous process monitoring and control.  

Research questions

  • How can formic acid be used as an energy carrier for power and heat generation?
  • Can CO2 electrolyzers be integrated into existing energy systems and operated with fluctuating electrical loads?
  • How can CO2 electrolysis be monitored and controlled under such conditions?
  • How can safe start-up and shut-down of the system be ensured?

Scientific approach and methods

First, a prototype of a CO2-to-formic acid electrolyzer will be set up in a laboratory.  One aim is the continuous process analysis using the most cost-efficient sensor technology possible. Furthermore, component and system models will be developed and integrated into the INSEL simulation environment. The models will then be validated in laboratory experiments and used for a simulation-based development of control algorithms for the electrolyzer. The control algorithms will then be tested and evaluated on the laboratory setup. The focus of the evaluation is on operation with fluctuating loads. The possibility of utilizing the hydrogen contained in the produced formic acid and thus obtaining a complete energy storage system will be investigated and the performance of the system evaluated on the basis of case studies.


  • Runnable laboratory prototype that can be operated permanently under fluctuating loads
  • Models for the components were created (INSEL)
  • Different scenarios for supply concepts with formic acid-based hydrogen storage were calculated
  • A guideline for system integration, dimensioning and operation was created


  • Integration of the test stand into teaching (project and final theses).
  • Further development of the project (upscaling, field trials)


Basics of electrolyzer modelling :

ManagementDr. Dirk Pietruschka
FundingVector Stiftung
Programme MINT-Innovationen



Name & Position E-Mail & Telephone
Institutsleiter; Stabstelle Forschung+49 711 8926 2674 7/032