Grid-forming inverters: SMA and M.O.E. put a new verification method into practice

- The M.O.E. Test Laboratory and the M.O.E. Certification Body, in collaboration with SMA, have completed a technically demanding verification process in accordance with VDE FNN Guideline 2.1


Itzehoe (renewablepress) - The manufacturer SMA has reached an important milestone in the development of grid-forming inverters. Following extensive testing, simulations, and model validations, the M.O.E. certification body has issued a prototype confirmation for grid-forming capabilities based on VDE FNN Guideline 2.1 for the Sunny Central Storage UP-S 4600 inverter with “Full Boost” current boost. This is the first prototype confirmation of its kind in the industry.

The project took a newly introduced technical requirement through the complete practical verification process: from the manufacturer’s development phase, through testing by the M.O.E. test laboratory, to independent evaluation by the M.O.E. certification body. In particular, the practical testing and validation of various simulation models presented significant technical challenges for all parties involved.

“My sincere congratulations go out to SMA and the entire project team. No established testing and certification process was simply followed here. The manufacturer, test laboratory, and certification body worked together to bring a new and technically demanding verification method into practical application. In many respects, this was true pioneering work.”
Tobias Busboom, Managing Director and Head of the EZE Certification Body and Test Laboratory, M.O.E.


Energy storage systems are taking on new roles in the power system

Battery storage systems are becoming a key component of a modern power system. They store energy when plenty of electricity is available and feed it into the grid when it is needed. In this way, they help better align weather-dependent generation and consumption over time and make locally generated energy available when it is needed.

At the same time, the decline in the use of large conventional synchronous machines is changing the technical characteristics of the grid. Functions that have been associated with these machines for decades must now be provided in other ways within a system increasingly dominated by inverters. Grid-forming inverters can contribute to this and, under defined conditions, provide inertia, among other things. As a result, battery storage systems are evolving from energy storage units into active system components.


Pioneering work in Test Laboratories and Certification

For the M.O.E. Test Laboratory, introducing the new testing procedures involved more than simply following the requirements. It was important to understand the technical background of the procedures and to connect the test methods with real operating conditions. The M.O.E. Certification Body then independently evaluated the results and assessed them within the new verification framework.

“With new requirements, experience is gained through practical application. It is not enough to simply check whether a measurement result falls within a specified tolerance range. We need to consider the measurements, test procedures, and real operating conditions together and understand what the results actually mean. Only on this basis can differences between measurements and simulations be properly assessed and models reliably validated.”
Michel Sievers, Deputy Director of the Test Laboratory, M.O.E.

A key focus of the project was model validation. The actual behavior of the inverter had to be matched against the measurements using different modeling approaches, including EMT and RMS models. Tight allowable deviations had to be considered alongside different simulation methods, measurement uncertainties, and dynamic effects. This required additional evaluation in several areas.


A collaborative effort by the industry

M.O.E. would like to expressly acknowledge the work of the experts who have laid the technical foundations for this type of verification in recent years. VDE FNN, FGW, and experts from grid operators, manufacturers, test laboratories, and certification bodies have invested significant resources in developing and defining requirements, measurement methods, modeling approaches, and certification processes, bringing them into practical form within a short period of time.

The experience gained from the first practical testing and certification projects will also contribute to the next stage of development. M.O.E. will bring the experience gained from this project into further technical and guideline development. Only when requirements, measurement practice, simulation, and certification continuously inform and improve one another can procedures be developed that are technically demanding while also being practical to apply.


From technical requirements to practical application

The technical challenge is clear: A power system with a high share of weather-dependent generation must provide energy reliably, when needed, and cost-effectively, while also maintaining system stability. Battery storage systems can combine flexibility with system services.

With SMA's successful prototype confirmation, this development has taken a significant step forward: a new technical requirement has become a practically tested and independently evaluated capability.

As the share of renewable energy increases, the way we ensure grid stability is evolving. Projects such as Blackhillock and Föhren have already demonstrated how battery storage systems equipped with grid-forming inverters can contribute to power system stability. With this prototype confirmation, we are laying the foundation for these capabilities to be used in the German inertia market.”
Daniel Duckwitz, Specialist Grid Stability, SMA


Itzehoe, 02 October 2026


Publication and Reprint free of charge; please send a voucher copy to M.O.E. Moeller Operating Engineering GmbH.


Attention editorial offices - For further questions please contact:

M.O.E. Moeller Operating Engineering GmbH
Kirchhoffstr. 1
25524 Itzehoe

Phone: +49 (0)4821 / 6453 100
E-Mail: info@moe-service.com

Internet: https://moe-service.com

---

Press release from the Renewable Energy Industry delivered by Renewable Press
Please note: The emittent / publisher »M.O.E. (Moeller Operating Engineering GmbH)« is responsible for all contents.