The Role of Battery Storage in the Energy Transition
The energy transition requires a transformation from fossil-based, centralized structures to decentralized, renewable systems. Battery storage plays a key role in this: It balances fluctuating feed-in, relieves grid loads, improves security of supply, and helps mitigate price fluctuations.
Legal Challenges of Grid Connection
However, challenges exist when integrating battery storage into the grid. While the legal connection requirement under Section 17 (1) of the Energy Industry Act (EnWG) has been clarified, technical grid capacity is often lacking. Section 17 (2b) of the Energy Industry Act (EnWG) offers solutions through flexible grid connection models. These enable the expansion of grid capacity and the joint operation of several systems. Section 8a of the Renewable Energy Sources Act (EEG) regulates such flexible agreements, which is particularly helpful in regions with weak grid capacity.
Problem of construction cost subsidies
A major problem remains the construction cost subsidy (BKZ), which places a financial burden on storage operators. The Federal Network Agency treats battery storage systems as final consumers during storage, which results in full BKZ costs. The Düsseldorf Higher Regional Court criticized this classification as too general, as it ignores the dual function of storage systems. Nevertheless, the Federal Network Agency adheres to this practice in its position paper from November 2024. Although the calculation model has been adjusted and discounts of up to 80% have been introduced in certain transmission grid areas, structural relief is lacking.
Outlook and necessary measures
A coherent, storage-friendly legal framework is needed for the effective ramp-up of storage projects. A paper from Working Group 15 from March 2025 offers hope for progress: Storage facilities should be located specifically at grid-friendly locations and classified as "in the overriding public interest." Tax relief and easier use of otherwise curtailed electricity are also planned. Whether these plans will take effect remains to be seen – but without clear regulations, the potential of battery storage will remain untapped.