Grid connection concept for battery storage and generation plants
Grid connection concept for battery storage: integrates generation plants and storage and delivers a robust, rule-compliant connection concept.
A future-proof energy supply needs intelligent, flexible and robust grid structures. We combine technical know-how with a systemic view of the entire grid, taking into account the regulatory framework, technical connection guidelines and economic aspects. For storage, the grid concept helps decide where and with what capacity a connection is possible.
We prepare an overall grid concept for you for integrating generation plants and storage. To do so, we carry out the grid compatibility assessment, evaluate the connection options and coordinate with the grid operator. Calculations use modern methods for load flow, short circuit, loss optimisation and thermal dimensioning. The grid compatibility assessment shows whether the grid can absorb or deliver the additional power; the result is the basis for the enquiry, permit and design.
The framework is clearly defined. The grid customer applies to the grid operator for the grid connection; the connection is made at the technically suitable grid connection point, not necessarily the most economical one. In the application, for storage the number, rated apparent power, capacity in kWh, coupling type (AC or DC) and operating mode are stated, and the grid operator can examine the use of equipment with possible grid perturbations and specify measures. For generation plants, the technical and organisational rules for operators and users of grids (TOR for generators) apply. The type classification follows the European grid code system: type B ranges from 0.25 MW to below 35 MW, type C from 35 MW to below 50 MW, type D starts from 50 MW or with a grid connection from 110 kV; the TOR version in force at the time is decisive. The requirements for reactive power, active power control and data communication rise with rated power; interface protection and data transmission depend on the plant configuration, the grid level, the TOR in force and the connection conditions of the grid operator, and for larger plants a central plant controller is often added. The grid operator responds to the application within the prescribed deadlines with a concrete proposal; a refusal is only possible on statutory grounds and must be justified in writing. For grid use, an energy supply contract and assignment to a balance group must be proven.
The regulatory framework is also evolving. The Electricity Industry and Organisation Act (ElWG), in force since December 2025, regulates, among other things, the transparency and reservation of available grid connection capacities; the market and grid-law status of storage depends on the electricity industry law applicable at the time of connection. Standardised metering concepts are being developed for storage and hybrid plants, for example with separate metering of charging and discharging for stand-alone storage. The required storage power follows from the load profile analysis for storage and grid. How storage interacts with wind and PV is shown by hybrid park planning with battery storage and grid. Cable routes and substations often affect protected assets, so the detailed nature conservation surveys belong in early. For generation plants there is the grid concept for wind farms and the grid concept for PV plants. The behaviour in the event of a communication link failure depends on the protection function, the plant configuration and the applicable connection requirements; reactive power specifications are possible from type B.
