Battery Storage Now Supports Grid Stability: SMA and M.O.E. Deliver Practical Proof for Grid-Forming Inverter
Itzehoe/Niestetal, Germany – SMA has received a prototype confirmation for grid-forming capabilities for its Sunny Central Storage UP-S 4600 battery inverter with "Full Boost". According to the certification body M.O.E., it is the first confirmation of its kind in the industry based on VDE FNN Guideline 2.1. The new verification procedure has thus been implemented in practice for the first time, from test measurements through model validation to certification.
SMA and M.O.E. Put New Verification Procedure into Practice for the First Time
For the prototype confirmation, the real-world behaviour of the SMA inverter was measured in the M.O.E. test laboratory and compared against various simulation models, including EMT and RMS models. According to M.O.E., narrow permissible tolerances, differing simulation methods, measurement uncertainties and dynamic effects required additional investigations.
After the tests were completed, the M.O.E. certification body assessed the results independently. For SMA, the prototype confirmation creates the prerequisite for also using the inverter's grid-forming capabilities in the German inertia market in future. The company points to battery storage projects such as Blackhillock in the UK and Föhren in Germany, where grid-forming inverters are already used for system stability tasks.
VDE FNN: Grid-Forming Inverters Can Provide Inertia
As conventional power plants decline, large synchronous machines, whose rotating masses help stabilise the power system, are increasingly leaving the grid. Grid-forming inverters can partly take over this function and, among other things, provide inertia. Inertia takes effect immediately in the event of an imbalance between power generation and consumption and limits rapid frequency changes. VDE FNN Guideline 2.1 defines the technical requirements and verification procedures for grid-forming systems.
Since January 22, 2026, the four German transmission system operators have been procuring inertia on a market basis. According to the grid operators, there is currently a significant need in all regions of Germany. For suitably qualified battery storage systems, this creates an additional field of use alongside power trading.
IWR: Battery Storage Affects More Than Electricity Prices – Additional Role in Grid Stability
Two different fields of use can be distinguished for battery storage. In classic energy storage, the focus is on exploiting price differences in the electricity market: storage systems charge when electricity prices are low, as low-cost wind and solar generation displaces more expensive power plants, such as gas-fired power plants, in the merit order. When prices rise again, they can feed the stored electricity back into the grid. As installed storage power capacity and storage capacity grow, battery storage can thus reduce the use of expensive power plants and lower electricity prices during high-price periods.
Grid stabilisation follows a different logic. The question here is not primarily when stored energy is sold again, but which technical functions a storage system can provide for the power grid. Grid-forming inverters enable battery storage to provide inertia, among other services, and thus take on tasks that have so far been performed largely by conventional power plants.
This additional storage function is aimed in particular at grid operators. With the market-based procurement of inertia, the transmission system operators have already created a procurement channel for it. For storage operators, this opens up an additional field of use in system services alongside the exploitation of price differences in the electricity market. The first prototype confirmation for the SMA inverter shows that the technical requirements developed for this purpose are now moving into practical testing and certification.
Source: IWR Online, 07 Oct 2026
