One million balcony power plants: The new solar boom in Germany!

One million balcony power plants: The new solar boom in Germany!

There are now around a million balcony power plants in Germany, also known as plug-in solar devices. This number has roughly doubled within a year. According to BSW managing director Carsten Körnig, he assumes that the one millionth device is already in operation. Balcony power plants are small solar systems that are often attached to balconies and have a connected load of 800 watts. When the sun shines, they feed their power into the home network via a socket, with surpluses being fed into the public network free of charge.

The market master data register currently shows 975,583 systems as being in operation, with around 20,000 of them temporarily or permanently shut down. However, these numbers often fall behind as they typically fall short of the actual number of balcony power plants. At the beginning of June 2024, half a million balcony power plants were already exceeded, and the BSW still sees no end to growth in sight for the future. Many people can imagine installing these devices, especially given the rising electricity prices after the start of the Ukraine war, which is seen as the initial spark for the boom.

Technical details and functionality

Balcony power plants consist of photovoltaic modules, an inverter, connecting cables and a substructure. They generate direct current, which is converted into alternating current via the inverter to be fed into the consumer circuit. These small systems offer an easy way to use self-generated electricity and actively support the energy transition, especially for tenants. They can serve as a precursor to larger photovoltaic roof systems, but the contribution to electricity generation is small compared to larger systems.

The Renewable Energy Sources Act (EEG) defines plug-in solar devices that only require registration in the market master data register with a module output of up to 2,000 watts and an inverter output of up to 800 watts. Temporary toleration of counters running backwards is permitted until they are replaced with bidirectional counters. Laypersons can carry out the commissioning themselves under certain conditions.

Distribution and market value

The geographical distribution of balcony power plants in Germany shows that most plants are in operation in North Rhine-Westphalia (194,077) and Bavaria (148,284), followed by Lower Saxony (127,879) and Baden-Württemberg (127,665). In cities such as Hamburg (7,202) and Bremen (5,118), there are significantly fewer systems, which is due to lower density in city states due to fewer suitable installation locations.

The prices for balcony power plants have fallen in recent years, which usually leads to a payback within a few years. Operators can register their systems without a feed-in tariff, as the feed-in tariff for plug-in solar devices is low (around 10 euros per year for 600 watts). Economic success depends heavily on the electricity you consume yourself.

Battery storage is often uneconomical for plug-in solar devices because their acquisition costs are high and usage is limited. In addition, the production of battery storage uses resources whose benefits for the energy transition are questionable.