SMA Solar Technology has received the first certification under a German VDE FNN guideline covering grid-forming capabilities and the provision of inertia, marking a step towards wider use of battery storage for grid stability services.
The certification applies to SMA’s Sunny Central Storage UP-S battery inverter platform and confirms compliance with version 2.1 of the VDE FNN guideline. The framework sets technical and verification requirements for grid-forming units and plants that could participate in Germany’s emerging market for inertia services.
Grid-forming inverters can help battery energy storage systems respond to changes in grid conditions and provide stability functions traditionally associated with synchronous generators. The technology is becoming more relevant as renewable generation and other inverter-based resources replace conventional generation.
Olaf Heyden, COO of SMA, said battery storage was increasingly taking on functions beyond energy shifting as electricity systems changed.
“With this certification, we are establishing an important prerequisite for the broader deployment of these technologies in the future and for actively supporting the transformation of the electricity supply,” he said.
SMA said the certification builds on previous work in grid-forming technology. The company received an earlier unit certificate for grid-forming battery inverters under Germany’s VDE-AR-N requirements in 2025. Its systems have also been deployed in battery projects including Blackhillock and Kilmarnock in the UK and the Föhren BESS in Germany.
The certification comes as Germany develops market mechanisms for inertia and other stability services. A standardised certification process could allow developers and system operators to assess grid-forming equipment against defined technical requirements.
Daniel Duckwitz, specialist grid stability at SMA, said projects such as Blackhillock and Föhren had provided operational experience with stability services from battery storage.
“With this certification, we are taking the next step towards establishing inertia services in Germany,” he said.
For battery project developers and utilities, grid-forming capability could create additional opportunities to provide system stability services alongside conventional storage functions, while giving transmission and distribution system operators another option for managing lower-inertia power systems.
