Requirements, Opportunities and MiSpeL Regulations for Mixed Operation

The MiSpeL decision puts an end to the uncertainty surrounding the mixed operation of battery storage systems. Clear requirements for metering, balancing, and settlement will enable a more flexible and efficient use of storage infrastructure in the future. Many large-scale battery storage projects face the same challenge: while the technical flexibility of modern storage systems is high, regulatory requirements have often imposed strict limitations. In particular, whenever different categories of electricity were to be utilized within a single storage system, operators and project developers quickly encountered regulatory barriers. With the publication of the latest working version of the MiSpeL decision, the German Federal Network Agency (Bundesnetzagentur) has now taken an important step toward the market integration of battery storage systems. The working version, published on 5 August, is currently scheduled to enter into force on 1 October 2026. According to the current plan, no further consultation process is foreseen.

For operators of large battery storage systems, this creates a clearly defined framework for so-called mixed operation for the first time and opens up new opportunities for the design and commercialization of storage projects.

Where Does the Problem Originate?

Until now, the operation of large battery storage systems has been heavily influenced by the origin of the stored energy. The joint management of electricity volumes with different remuneration schemes within a single storage system was not permitted under existing regulations (principle of exclusivity). In practice, this meant that renewable electricity (“green power”) and conventionally sourced grid electricity (“grey power”) applications had to be strictly separated. As a result, flexibility potentials, meaning available storage capacities, could often not be utilized optimally, reducing both economic efficiency and grid-supporting benefits.

Particularly at sites with existing generation assets, grid connection points, and fluctuating consumption profiles, this created significant limitations for the development of optimized operating concepts.

What Is the MiSpeL Decision About?

The MiSpeL decision now establishes the regulatory framework for operating large battery storage systems in mixed operation. This allows electricity volumes subject to different remuneration schemes to be charged into and discharged from the same storage system. A prerequisite for this is the so-called “separation option” (Abgrenzungsoption). This mechanism provides both metering and computational separation of the respective energy volumes, ensuring that the different categories of electricity can be clearly assigned.

As a result, battery storage systems can be used far more flexibly and can be tailored more effectively to the specific requirements of individual sites. besser an die jeweiligen Anforderungen eines Standorts angepasst werden.

How Are the Energy Volumes Separated?

The MiSpeL decision defines the requirements for recording and separating the relevant electricity volumes.

In particular, the following must be measured using separate calibrated meters:

• Feed-in from renewable energy systems

• Grid electricity consumption

• Battery charging processes

Measurements must be recorded in 15-minute intervals. In addition, the applicable formulas as well as the permissible settlement and metering concepts for separating the energy volumes have now been defined. This creates the necessary foundation for the legally compliant implementation of corresponding storage concepts.

Why Is This Relevant for Storage Projects?

The decision opens up additional opportunities for the operation and commercialization of battery storage systems. Depending on the existing generation, consumption, and grid conditions, storage systems can now be deployed more flexibly. At the same time, new options emerge for marketing the stored energy. However, the increased flexibility also affects technical implementation. Operating concepts become more complex and place greater demands on control systems and energy market optimization. Consequently, high-performance energy management systems and experienced market access partners will become increasingly important.

This development is particularly attractive for industrial customers with their own generation assets, fluctuating consumption profiles, and existing grid connection points. In such cases, battery storage systems can be adapted more closely to local conditions and deployed in a more targeted manner.

Our Solution

At the same time that new regulatory opportunities emerge, the requirements for planning and implementing storage projects also increase. A key success factor will be the early integration of suitable operating, metering, control, and commercialization concepts during the initial project phases. Only in this way can the full potential of battery storage systems be unlocked and the additional system flexibility be optimized economically. Kumandra supports customers in integrating regulatory requirements into both the technical and economic development of projects at an early stage and in developing suitable concepts for future storage operations.

Fazit

With the MiSpeL decision, the German Federal Network Agency has established a clear regulatory framework for the mixed operation of large battery storage systems for the first time. The defined requirements for metering, balancing, and settlement provide planning certainty and enable new operational and commercialization models.

From our perspective, this is an important step toward utilizing existing storage infrastructure more efficiently and adapting battery storage systems more closely to site-specific conditions. Industrial sites with existing generation assets and grid connections, in particular, stand to benefit from new opportunities.

Over the coming months, it will become clear how these new possibilities are implemented in practice. What is already evident today is that the new regulations create additional flexibility for the development and commercialization of modern battery storage projects.

Note: This article reflects our practical experience and does not constitute legal advice.