One million balcony power plants on the grid

12.06.2025

Source: E & M powernews

Balcony power plants have exceeded the one million mark in Germany. The boom is increasingly reaching urban forms of living.

Compact solar systems that feed directly into the household grid via a socket are becoming increasingly popular in Germany. According to estimates by the German Solar Industry Association (BSW Solar), these so-called plug-in solar devices, also known as balcony power plants, exceeded the one million installed systems mark in June 2025. The calculation is based on data from the Federal Network Agency's market master data register.

Since June 2024 - when the figure was around half a million - the number of registered systems has almost doubled. The register currently has around 975,000 active entries, plus around 20,000 temporarily or permanently decommissioned devices. The actual number is likely to be higher, as operators have up to one month to register.

Strong demand in apartment buildings

According to the association, the devices are easy to install on balconies, house facades or in the garden and do not require complex electrical installations. In cities in particular, they enable tenants to participate in decentralized power generation for the first time. According to BSW Solar, around 135,000 new systems were added between January and April of this year alone - an increase of 36 percent compared to the same period last year. The installed capacity of these new installations rose by around 75 percent.

According to a representative survey by the opinion research institute "YouGov", eight percent of the population are planning to purchase such a device this year. A further nine percent show a general interest. According to the comparison portal Verivox, nine percent of those surveyed have already installed a balcony power plant.

The legally permitted output is limited: A maximum of 800 watts may be fed into the domestic grid as alternating current, while the solar modules themselves may generate up to 2,000 watts. Systems with battery storage are subject to stricter requirements and are not considered plug-in solar devices.

Legal simplifications promote expansion

Legal adjustments in recent years have made installation much easier. For example, the law now stipulates that landlords or owners' associations may not prohibit installation without further ado. Approval from the grid operator is no longer required. However, the obligation to register in the market master data register still exists (we reported).

Regional growth is also clearly noticeable - especially in densely populated federal states. The highest numbers were recorded in North Rhine-Westphalia (194,000), Bavaria (148,000), Lower Saxony and Baden-Württemberg. In city states such as Berlin, Hamburg and Bremen, the spread is significantly lower - partly due to a lack of installation space and building restrictions.

Visible energy transition in everyday life

Taken together, the plug-in solar devices registered to date have an output of just under 900 MW. Their share of total electricity generation therefore remains low. However, BSW Solar rates their importance for the acceptance of the energy transition as high: they enable citizens to actively participate in the transformation of the energy system and influence their own electricity consumption.

BSW Managing Director Carsten Körnig expects this trend to be reflected more strongly in the cityscape in the future: "Now that solar roofs have long been standard in housing estates, the solar boom on balconies will increasingly shape the image of city centers."

Author: Davina Spohn