A German homeowner is raising concerns about a recent change in how electricity generated from balcony solar panels, known as “Balkonkraftwerke,” is calculated for feed-in tariffs. The homeowner, who has a 5.13 kWp rooftop solar system and a 2000W Balkonkraftwerk with a 3.2kW storage system, reported receiving a lower overall feed-in rate after adding the balcony system, despite increasing total electricity fed into the grid.
The homeowner, who asked to be identified only as Lothar, stated that the calculation appears to be based on the installed capacity of both systems, rather than the actual output of the Balkonkraftwerk, which is limited to 800W via the standard socket connection. “It’s illogical,” Lothar wrote in a forum post, “because the Balkonkraftwerk only contributes 800W, even if I had 10,000W of solar power.”
The issue stems from a provision within the German Renewable Energy Sources Act (EEG), specifically §24 paragraph 3, as clarified by Lars, another forum user. This section stipulates that for systems utilizing similar renewable energy sources, the allocation of electricity generated is determined proportionally to the installed capacity of each system. According to the EEG, this applies to all systems except those with specific agreements.
The change in calculation methods follows revisions to regulations surrounding Balkonkraftwerke, including the introduction of the VDE-AR-N 4105 standard in December 2025. This standard, as reported by energiemagazin.com, aims to clarify the safe and compliant connection of these systems to the grid. The novel regulations allow for systems up to 2,000W peak (Modulleistung) and 800 Voltampere (VA) of inverter output, categorized as a “simplified” standard case.
While the VDE standard permits connections via standard Schuko sockets, it limits the permissible module output to 960W. Higher outputs, up to 2,000W, require alternative connection methods like Wieland connectors or other compliant solutions. The ADAC reports that Balkonkraftwerke can cover 10 to 20 percent of a household’s annual electricity needs if optimally positioned, and sized.
Currently, over 1.2 million Balkonkraftwerke are in operation across Germany, according to the Federal Network Agency. The increasing popularity of these systems is driven by a desire for energy independence and reduced electricity costs. However, the homeowner’s experience highlights a potential unintended consequence of the new regulations, where the addition of a Balkonkraftwerk may negatively impact the overall feed-in tariff received for all generated electricity.
The homeowner’s concerns remain unresolved, with no immediate clarification available regarding the specific calculation methodology employed by their electricity provider. The next scheduled review of the EEG is not specified, leaving the homeowner awaiting further guidance on the matter.
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