Green Co-Located Storage in Regulatory Context

(Status as of May/June 2026: All measures described are still subject to ongoing legislative or regulatory proceedings.*)

2026 marks a regulatory turning point for battery storage in Germany. Rarely before have so many fundamental regulatory frameworks been reformed at the same time: from the amendment of the Renewable Energy Sources Act (EEG) and the reform of the General Electricity Network Tariff System (AgNes) to the Grid Connection Package and the amendment of the Federal Building Code (BauGB).  

Green co-located storage systems are set to benefit especially from this. Planned legislative and regulatory reforms aim to further integrate battery storage with renewable energy assets and strengthen its role in the energy system. At the same time, some of the proposed measures raise new questions regarding project economics and investment certainty. 

For operators, and investors, this creates a dynamic landscape of expanded market opportunities, new regulatory requirements, and shifting revenue streams. The following provides an overview of the most important developments affecting green co-located storage and what they mean for operators and investors.  

Distinguishing Between Co-Located Storage and Green Co-Located Storage

The terms "co-located storage" and "green co-located storage" are often used interchangeably. In fact, they describe distinct concepts with important regulatory implications.  

• A co-located storage system is installed alongside a renewable energy asset. However, this does not determine the source of electricity used to charge the battery. The system may draw electricity either from the connected renewable energy asset or from the grid.  

  
  

• A green co-located storage system goes one step further: it is charged exclusively with electricity generated by the directly connected renewable energy asset and draws no electricity from the grid. Only under this condition does the electricity subsequently fed into the grid remain eligible for support under Section 19 (3a) of the Renewable Energy Sources Act (EEG). Even small amounts of grid-sourced electricity may result in the loss of EEG eligibility.

  
  

In short, every green co-located storage system is a co-located storage system, but not every co-located storage system qualifies as a green co-located storage system. The term green co-located storage refers to co-located systems without grid charging that preserve EEG eligibility for electricity generated by the directly coupled renewable energy asset. 

Co-Location Is Explicitly Encouraged – But Not Without Contradictions

Co-located models, and green co-located storage projects in particular, currently benefit from strong regulatory tailwinds. Under the German Federal Building Code (BauGB), battery storage systems already qualify as privileged developments if they are located in a “spatial and functional relationship” with a renewable energy installation. According to the current cabinet decision on the BauGB, this privileged status for projects in undeveloped outdoor areas under Section 35 (BauGB) will continue to apply.^[1]

The ongoing reform of the Renewable Energy Sources Act (EEG)^[2] also sends clear signals in support of green co-located storage. In addition to providing a reliable expansion pathway for wind and solar energy, which further increases the need for flexibility, the draft bill published in late April 2026 explicitly states: 

„The combination of renewable energy installations with storage systems can enable more demn-oriented feed-inof electricity and help absorb generation peaks. Particularly for solar installations, the standard approach should be to deploy storage alongside the generation asset from the outset.“ – EEG 2027 draft amendment

This objective is also reflected in the specific provisions. For example, small-scale PV-systems will be required to permanently limit their feed-in capacity to 50 % of installed capacity. The intention is to shift generation peaks to higher-value hours and thereby increase the economic rationale for deploying storage.  

The draft also proposes extending municipal participation payments to electricity that is temporarily stored (EUR 0.002/kWh based on the electricity generated). On the one hand, this introduces an additional cost component for co-located projects, which may slightly reduce project margins. On the other hand, broader municipal participation is likely to increase local acceptance of such projects.   

CfD in the EEG-Draft: Implications of the Clawback Mechanism

At the same time, this draft includes a mechanism that does not work in favor of green co-located storage within the EEG support scheme. For installations with a capacity of 100 kWp or more, a two-sided Contract for Difference (CfD) will be introduced. If the technology-specific annual market value falls below the applicable reference value , the operator receives a market premium. If it exceeds the reference value, the operator is required to make a refinancing contribution (clawback).

A key consideration for green co-located storage: the clawback is explicitly intended to apply to electricity that is first stored and only fed into the grid at a later point in time.^[3] Simultaneously, the current draft no longer includes a market value corridor. The clawback therefore takes effect immediately once the annual market value exceeds the reference value. 

For low but still positive electricity prices, a dynamic calculation of the refinancing contribution applies. In these cases, the contribution is no longer based on the difference between the annual market value and the reference value, but on the difference between the current spot market price and a predefined minimum revenue level.  

This clawback mechanism is particularly relevant for green co-located storage, as its value creation largely depends on shifting electricity generation to higher-priced hours. A significant share of the additional revenues generated through this flexibility may be subject to the clawback mechanism. As the proportion of green co-located storage in the system grows and the solar reference market value potentially shifts, this effect could become increasingly important.  

This raises the question of which route to market will be more attractive in the long term: the EEG support scheme with its revenue protection mechanisms or merchant market participation without public support but with greater exposure to market prices. The answer will depend on the specific project structure, the final design of the regulatory framework and, not least, the optimization strategy pursued.  

MiSpeL and AgNes Create a New Framework

Furthermore two ongoing Federal Network Agency (BNetzA) proceedings are especially relevant for green co-located storage: MiSpeL and AgNes. Both are set to fundamentally reshape the regulatory framework for energy storage by enabling greater operational flexibility while also introducing new requirements for metering, billing and network charges.  

MiSpeL: Greater Flexibility For Green Co-Located Storage

Starting in July 2026, the Market integration of Storage and Charging Points (MiSpeL)^[4] framework is intended to eliminate the current all-or-nothing approach for green co-located storage. Under the current rules, a storage system remains eligible for EEG support only if it is charged exclusively with renewable electricity. Even a single kilowatt-hour of non-renewable electricity can result in the loss of EEG eligibility. In practice, this often leaves storage systems underutilized at night or during winter periods and limits the participation in balancing markets.

MiSpeL removes this binary approach and introduces two new accounting models. For systems of 30 kWp and above, the segregation option under Section 19 (3b) EEG enables quarter-hourly metering and the separate accounting of renewable and non-renewable electricity. For smaller systems of up to 30 kWp, the flat-rate option under Section 19 (3c) EEG provides a simplified accounting approach without the need for interval metering. 

As a result, co-located storage systems will be able to draw electricity from the grid at night, participate in FCR and aFRR balancing markets, and still retain EEG eligibility for the renewable share of their electricity feed-in. For the first time, this creates a practical framework for genuine multi-use operation, including participation in both spot and balancing markets. 

AgNes: Reforming Netzwork Charges

The reform of AgNes, which is scheduled to take effect in 2029, will also be highly relevant for operators of generation assets and battery storage systems. According to the current proposal, asset-coupled storage systems, including green co-located storage, will be treated jointly with the associated renewable energy asset for the purpose of network charges. Rather than introducing a separate charge for the storage system, only a single capacity charge would apply at the respective feed-in or withdrawal point. 

Another important aspect concerns volumetric charges: electricity drawn from the grid and subsequently fed back into the system by a storage asset is expected to be exempt from volumetric charges, provided an appropriate metering concept is in place. By contrast, no volumetric charge would apply to behind-the-meter electricity volumes. 

Dynamic network charges are expected to be introduced for storage systems no earlier than 2030 and for generation assets from 2032 onwards. In the long term, they could create additional incentives for grid-supportive storage operation.  If temporally and spatially differentiated tariff components are designed appropriately, they can reward flexibility where it delivers genuine systemic value. This could unlock additional value streams, particularly for co-location projects that promote grid-supportive generation behavior, especially where generation, storage and grid usage are intelligently coordinated. 

At the same time, the reform provides planning certainty for projects that are already underway. Existing installations, as well as projects for which a final investment decision (FID) was taken before the framework ruling enters into force and which are commissioned by 4 August 2029, will retain their existing protection of legitimate expectations, provided the framework ruling enters into force as currently expected by the end of 2026. These projects will remain exempt from the new network charging framework for up to 20 years. 

What This Means for Optimization and Trading

The current regulatory developments all point in the same direction: the importance of intelligent trading and optimization solutions for battery storage is growing. As fixed support mechanisms are gradually phased back and market integration increases, revenue opportunities are increasingly shifting towards wholesale and balancing markets. At the same time, complexity is increasing. New network charging structures, potential additional levies and the CfDmechanism are reshaping the economic framework for storage projects. MiSpeL opens up additional routes to market: once co-located storage systems can actively participate in markets overnight and during winter, the number of economically viable operating hours increases significantly. The storage asset is increasingly becoming a fully-fledged flexibility asset. 

For operators of green co-located storage, this means that regulatory developments are creating new opportunities while simultaneously increasing the demands placed on commercial optimization and operations. The ability to optimize storage assets flexibly across day-ahead, intraday and balancing markets, while responding to changing market and regulatory conditions, will become increasingly important. 

For further Reading

More Data

Learn more about the opportunities and revenue projections for green electricity suppliers (for 2024) in our article Challenge Green Co-Located Storage.

Look at Real-World Projects

Learn more about how green energy storage projects are implemented in practice in our case study in collaboration with Prokon eG.

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*Timeline: 1 July 2026 – MiSpeL determination · Earliest 10 June 2026 – EEG cabinet decision · June/July 2026 – AgNes draft determination · Q4 2026 – Expected entry into force of the EEG 2027 reform and BauGB amendment · End of 2026 – AgNes framework determination · 1 January 2029 – New network charging framework enters into force.

^[1] On 27 May 2026, the German Federal Cabinet approved the amendment to the Federal Building Code (BauGB). The original draft bill also included a 100–200 metre setback requirement ("swimming ring rule") for standalone storage systems in undeveloped outdoor areas. While this provision was removed from the cabinet draft, it is expected to remain part of the parliamentary debate. As a result, the planning and permitting framework for standalone storage projects remains subject to further developments. Another new element is the introduction of FNP privileging. In the future, municipalities will be able to determine which projects are permissible in undeveloped outdoor areas through the land-use plan (Flächennutzungsplan) rather than through a local development plan (Bebauungsplan). This will be possible even if a project does not meet the previously applicable strict requirements, such as minimum capacity thresholds or setback distances, provided it is considered "desirable or necessary from an urban planning perspective". 

^[2] Since the publication of the draft amendments to the Renewable Energy Sources Act (EEG) and the Energy Industry Act (EnWG) in late April 2026, discussions within the government have intensified. A cabinet decision is expected on 10 June, while the parliamentary process is set to begin before the summer recess. The timeline is tight, as the new clawback mechanism must be implemented in line with EU requirements by July 2027 at the latest. 

^[3] cf. the explanatory memorandum to Section 20a in conjunction with Section 19 (3) to (3b) of the Renewable Energy Sources Act (EEG)

^[4] On 18 September 2025, the Federal Network Agency (Bundesnetzagentur) published its draft determination on the Market Integration of Storage and Charging Points (MiSpeL, Case No. 618-25-02). The final determination is required to enter into force by 1 July 2026. 

^[5] On 27 May 2026, the Federal Network Agency (Bundesnetzagentur, BNetzA) presented its preliminary position on the reform of the General Electricity Network Charges Framework (AgNes). A draft determination is expected by the end of June 2026, while the final framework determination is scheduled for adoption by the end of 2026. The new framework will take effect in 2029.