For some commercial PV systems There is an often overlooked risk: If a Regulation the connection technically only at the inverter, the grid operator not only cuts off the feed-in to the public grid during grid bottlenecks - but also the Own consumption. This results in self-generated solar power remaining completely unused, even though it could be consumed on-site.
The relevance of the topic is shown by the current figures from the Federal Network Agency: In 2024, grid operators had to implement grid bottleneck management measures with a volume of well over 30,000 gigawatt-hours seize. The curtailment of photovoltaic systems rose to almost 1,400 gigawatt-hours – an increase of almost 100 percent compared to the previous year. The main drivers were the massive increase in PV capacity and the exceptionally high solar irradiation in the summer of 2024.
Economically, this is not a niche issue either: The total costs of grid congestion management amounted to 2.8 billion euros. For the curtailment of renewables alone,"} 554 million euros an equalization payment – despite falling wholesale prices. For operators, this means: those who do not have a technical solution for a curtailment at the feed-in point risks unnecessary yield losses and squanders self-consumption potential.
The Legal Framework: Clear Protection for Self-Consumption
Both European and German law provide special protection for the self-consumption of photovoltaic electricity. In Article 13 of the EU Regulation on the internal market for electricity (EU) 2019/943 is stipulated that self-generated electricity that is not fed into the grid is fundamentally not subject to Redispatch- May be measures or curtailments. Only when there is absolutely no other possibility to ensure grid stability may self-consumption also be reduced or completely switched off.
The Renewable Energy Sources Act (EEG) obligates operators of PV systems above a certain output § 9 EEG, to provide technical facilities with which the grid operator can remotely reduce the feed-in power. The goal is to avoid grid bottlenecks and ensure grid stability. However, the EEG does not explicitly regulate that only grid feed-in may be affected – the technical implementation is left to the operators.
The Energy Industry Act (EnWG) supplements these requirements: After § 13 Paragraph 1 of the Energy Industry Act Network operators are authorized to limit or temporarily disconnect systems from the grid in terms of their active power if the grid's security is endangered. However, here too, the measure must be proportionate – meaning it must not interfere with operation any more than necessary to secure the grid. In practice, this means: the reduction should only affect grid feed-in, not self-consumption.
However, if there is no corresponding technical implementation, the grid operator can unintentionally shut down self-consumption by throttling the inverter. This not only leads to economic losses but also contradicts the fundamental idea of the EEG, which promotes self-consumption as a contribution to the energy transition.
Why self-consumption can still be affected in practice
Despite these clear regulations, in practice, grid operators sometimes also curtail self-consumption. The main reason for this lies in the technical implementation: if an inverter is directly throttled down, the entire PV production is reduced—regardless of whether the electricity is fed into the grid or consumed on-site.
In many cases, the measurement separation between feed-in and self-consumption. Without suitable control technology, grid operators cannot determine exactly how much of the generated electricity actually flows into the grid. In addition, some grid operators use standardized control commands that reduce the total output across the board. This means that legally protected self-consumption is not always left untouched in reality.
Technical requirements for the protection of self-consumption
So that self-consumption remains available even in the event of curtailment, the PV system must be equipped accordingly. An intelligent metering system is the basis for distinguishing between self-consumption and feed-in. Additionally, a Energy management systemhow the CUBE EfficiencyUnit, for the fact that solar power is preferentially distributed to operational consumers such as production facilities, heat pumps, or charging infrastructure before surpluses go into the grid.
Especially helpful are Large-scale battery storage, which can absorb excess electricity when grid operators limit feeding into the grid. This way, this electricity is available for self-consumption at a later time. The inverter also plays a central role. Modern devices can be configured to reduce feed-in power without interrupting the supply to self-consumers. Additionally, measuring and control boxes on the system side enable precise power regulation that only affects grid consumption.
Practice at CUBE CONCEPTS: Limiting only at the feed-in point
At CUBE CONCEPTS, all commercial PV systems and large-scale battery storage systems are designed and implemented as standard using the CUBE EfficiencyUnit as the EMS. This allows for targeted curtailment at the feed-in point—while ensuring that power supply to on-site consumers remains unaffected. This technical implementation ensures that self-generated solar power remains available for operation even during grid congestion or redispatch measures. For customers, this means maximum supply security and optimal utilization of the PV system—regardless of external grid restrictions.
How companies can prevent the curtailment of self-generation
To ensure that self-consumption is not unnecessarily restricted, one should technically upgrade their PV system and at least implement a feed-in management system. This includes clear communication with the grid operator about which plant capacity is exclusively reserved for self-consumption. Regular review of the system configuration is also important, as legal requirements can change due to EEG amendments and adjustments in the EnWG.
Uninterrupted documentation of all technical measures and coordination with the grid operator can be crucial in a conflict situation. It shows not only that the system complies with legal requirements, but also that all options for securing self-consumption have been exhausted.
Incomplete implementation leads to curtailment of PV self-consumption
Large commercial PV systems enjoy clear legal protection for self-consumption. However, practice shows that this protection is not always effective without the right technology. Therefore, companies that rely on self-supply should invest early in intelligent metering systems, energy management, storage solutions, and controllable inverters. CUBE CONCEPTS is already committed to the consistent implementation of these technical standards here – and thus ensures that self-consumption is reliably secured, even in times of grid bottlenecks.