Munich, July 15, 2025 — The Federal Court of Justice (BGH) today approved the collection of construction subsidies (BKZ) for battery storage systems. At the heart of the process initiated by Kyon Energy was the question of whether network operators for stationary battery storage systems may demand construction subsidies indiscriminately from end users, even though they relieve the electricity system and do not act like traditional end users. The consequences of the decision are far-reaching — for investment security in large battery storage systems, for the planning practice of project developers and for the framework conditions of the energy transition — and raise fundamental questions regarding the scope of action of the Federal Network Agency (BNetzA).
The Federal Court of Justice has overturned the decision of the Düsseldorf Higher Regional Court (Higher Regional Court). The decision formally relates to an individual battery storage system from Kyon Energy, which was made the subject of the proceedings. Overall, however, it can be assumed that the decision applies in principle to battery storage systems. However, the full scope will only be assessed on the basis of the Federal Court of Justice's reasons, which are not yet available today.
Many experts see the regulation currently practiced by various grid operators as a fundamental design flaw: Large-scale battery storage systems pay like traditional end users, although — in two ways atypical compared to final consumers and other network users — they draw in when there is a surplus of electricity, and also contribute to grid stability.
From a legal point of view, it is surprising and regrettable that the case was not referred to the European Court of Justice, especially since the Düsseldorf Higher Regional Court based its dissenting decision centrally on considerations of European law. With today's decision, the Federal Court of Justice also gives the BNetzA room for manoeuvre that cannot be reviewed by the court.
“In view of the fact that BNetzA, as an independent regulatory authority, is already removed from the control of national legislators, today's decision raises questions of European law of unforeseeable significance. More than BKZ will be at stake in future decisions and it is to be hoped that the supervisory bodies for BNetzA will then fulfill their role,” comments Benedikt Deuchert, Head of Business Development & Regulatory Affairs at Kyon Energy.
The starting point was a battery storage project by Kyon Energy, for which a grid connection was applied for in 2021. On the basis of the BNetzA position paper, the responsible network operator demanded a construction subsidy, which Kyon Energy considered inadmissible. As part of abuse proceedings at the Federal Network Agency, the collection of construction subsidies should be prohibited. With ABO Energy and ju:niz Energy, two other leading players in the storage sector have joined the process. The BNetzA did not follow Kyon Energy's arguments and thus confirmed the action of the responsible network operator. In December 2023, the Düsseldorf Higher Regional Court decided that the BNetzA's decision should be repealed: The calculation model underlying the BKZ survey disadvantaged large battery storage systems and violated the Energy Industry Act. The BNetzA filed a legal complaint against this with the Federal Court of Justice — the BGH's decision has now been submitted.
Kyon Energy is a leading German project development company that focuses on large battery storage systems and, in addition to project planning, also acts as an EPCM (Engineering, Procurement, Construction, and Management) and operator of the plants. With 135 MW of battery storage systems successfully developed and sold, over 1.7 GW of approved and ready for construction projects and a current project pipeline of over 7 GW, Kyon Energy is one of the market leaders in Germany. The company, which was acquired by TotalEnergies in January 2024, has a particular focus on the development and optimization of multi-use strategies, combined with deep expertise in project development and management as well as the regulation of large battery storage systems. Through its battery storage systems, Kyon Energy is a driver of the energy revolution and strives for a world powered by renewable, sustainable and independent energy.
.avif){kind=logo}
