Energy Storage

Medium Voltage – Energy Storage
© Fraunhofer ISE

For a reliable electricity supply based on 100% renewable energies, extensive decentralized and centralized stationary battery storage systems and chemical storage systems are essential. Medium-voltage transformers enable an efficient connection to the medium-voltage grid and grid management is optimized by power electronics.

One of the main tasks of electrical storage systems is to keep the electricity grid stable and fail-safe in the face of fluctuating feed-in from photovoltaics and wind. In addition, decentralized storage systems in industry and commerce allow the producers to increase their solar self-sufficiency. Storage systems offer economic and ecological savings potential in the face of sharply rising energy market prices. Intelligent power electronics and energy management systems optimize the interaction between generators, consumers, storage systems and power grids.

Chemical storage systems are used to decarbonize industrial processes and store renewable energy over the long term. Hydrogen production in electrolyzers is a clean and efficient process that only requires water and electricity. If hydrogen is produced with renewable electricity as a mandatory requirement, we have a sustainable energy source for storing renewable energy.

With the help of medium-voltage transformers, these storage systems can be connected directly to the medium-voltage grid and thus efficiently store renewable energy temporarily. In addition to the pure feed-in or feed-back of electrical energy, medium-voltage power electronics can also assume other grid-supporting tasks.

R&D Services

We provide R&D services for manufacturers of power electronic devices and systems, stationary battery storage systems, hydrogen generation systems as well as energy suppliers, transmission system operators, power plant operators, project developers, plant planners, system integrators and system manufacturers. Our range of services include:

  • Development of efficient high-power electronics converters for low and medium-voltage applications
  • Feasibility and concept studies for high-power systems
  • Advice and expert opinions on power electronics issues
  • Development of safe, reliable and efficient battery systems
  • Concept development and operational management strategies for optimized technical integration and grid stability
  • Development and evaluation of hydrogen infrastructures and electrolyzers
  • Troubleshooting and error analysis both in the lab and on the field

Our R&D Infrastructure on this Topic


R&D Infrastructure

Center for Power Electronics and Sustainable Grids

  • Independent connection to the high-voltage grid
  • Power electronics in the multi-megawatt range in low and medium voltage
  • Highly dynamic 1 MVA grid simulator 
  • The Power Converters Lab, Digital Grid Lab, Multi-Megawatt Lab and Medium Voltage Lab provide unique opportunities for research and development in the field of power electronics and dynamic grid control.

Medium Voltage Lab


Center for Electrical Energy Storage

Novel materials and innovative production processes for battery systems technology


Center for Fuel Cells, Electrolysis and Synthetic Fuel

Characterization of components for hydrogen technology


Accredited Lab

TestLab Power Electronics

Testing and characterization of power converters up to the multi-megawatt range.

Selected Research Projects



Medium-voltage Converter with High-voltage SiC Power Modules for Large-scale Storages and System-serving Distribution Grids



Hydrogen production at sea by PEM water electrolysis

Further Information on this Research Topic


Power Electronics and Grids


Electrical Energy​ Storage


Hydrogen​ Technologies​