Germany is witnessing a solar surge from an unexpected place: its balconies. According to a recent estimate by the German Solar Association (Bundesverband Solarwirtschaft e. V., or BSW-Solar), the number of registered plug-in solar devices—commonly known as “balcony power plants”—is expected to reach one million by the end of June. Based on current data from the Federal Network Agency (Bundesnetzagentur, BNetzA), the association believes this milestone has likely already been surpassed, as official registrations often lag by several weeks.

Balcony solar systems have become an increasingly popular solution for renters and apartment dwellers seeking to generate their own electricity and lower their utility bills. These compact, plug-in units can be installed with minimal effort and typically pay for themselves within just a few years.

A recent survey by YouGov, commissioned by BSW-Solar at the end of 2024, shows that the momentum is far from slowing: 8% of respondents said they plan to purchase a plug-in solar device this year, with another 9% intending to do so in the future. From January to April 2025 alone, approximately 135,000 new devices were brought online, representing a 36% increase compared to the same period in 2024. The power output from these new systems rose by an impressive 75% over the same span.

“Now that rooftop solar has become the norm in residential areas, plug-in solar will increasingly shape the appearance of urban neighbourhoods,” said Carsten Körnig, CEO of BSW-Solar. “More and more people are benefiting from the solar transition.”

Consumer-Friendly, Safe, and Scalable

Plug-in solar devices differ from traditional photovoltaic systems in that their limited power output minimises any risk to a building’s existing electrical infrastructure. Under draft standards from the VDE (German Association for Electrical, Electronic & Information Technologies), module output is capped at 2,000 watts, while AC output from the inverter must not exceed 800 watts.

The simplified regulatory framework has helped accelerate adoption. Today, no landlord approval is required, and installation is straightforward. However, registration in the Federal Network Agency’s market data register is mandatory within one month of installation.

Only systems without battery storage qualify as plug-in solar devices under current regulations. Systems that include energy storage must still be installed by certified electricians and registered with the grid operator.

With plug-in solar now becoming a fixture on balconies across the country, Germany continues to demonstrate how clean energy can be scaled through accessible, citizen-driven solutions.