Mini solar systems or plug-and-play PV systems are terms commonly used on the market without an exact legal definition.

In the standards of the VDE, which again have no legal or legally binding character, there are the following definitions:

Consumer power plants (ready-to-plug-in generator systems) may simply be connected by means of a socket in the house grid. A connection to the house distribution board is not mandatory if they do not exceed a power of 3.68kW maximum grid load. This does not require an application for approval or acceptance by the grid operator. A notification of commissioning for outputs up to 3.68 kW using a special simplified form for this purpose and the signature of a registered specialist company are sufficient.

The 600W for balcony power plants mentioned in the usual forums, which represent the maximum output power of the microinverter, not the power of the PV modules, are neither regulation nor standard. It has merely been agreed in professional circles to accept this above-mentioned simplified registration without an electrical contractor signing this simplified registration.

The corresponding EU directive with an upper limit of 800 W, which applies e.g. in Austria, has not been transposed into German law by Germany. This means that in Germany there is no limit, however defined, for an 800 W balcony power system.

There is another figure that is mentioned from time to time, and that is 4600 watts. With this power, a single-phase PV system can be connected directly to the distribution system. However, this is definitely a matter for the electrical specialist. Above 4.6 kW, only 3-phase inverters may be used. (heavy current 400V). The HMT-1800/2250 3-phase micro inverters with 6 modules that can be ordered must always be installed by a specialist contractor.


In Germany, any person can purchase, set up and commission a balcony power plant (plug-in generating units) without violating any law. A notification to the market master data register is uncomplicated, online and done in a few minutes. If he wants to comply with the VDE standard, a simplified notification must be made to the grid operator, without any legal obligation on their part through a law. Anyone who wants to operate a balcony power plant with more than 600W of microinverter output power can do so up to 3.68 kW, but at present in Germany they cannot register themselves using the simplified procedure. If you want to be sure that the installation is VDE-compliant, you can secure yourself by calling in a specialised electrical company. A risk of power overload will certainly be minimal in the range of 1 to 2kW. In addition, Plug Solar recommends an inspection by a specialist company. So if, for example, you want to double your balcony power plant with 1.2 kW or 2.4kW or

What are balcony power plants – Status 12/2021

can do so, but should call in a specialist company at their own discretion and have the cables tested. The commercially available feed-in sockets can also be used up to 3.68 kW inverter power, if desired. A direct connection to the power line is also possible at any time, but according to VDE it is actually also a matter for the specialist company, since as a layman you are not even allowed to change a socket or a light switch.

Background information:

The micro inverters marketed by Plug Solar are CE-tested and designed in such a way that they must first synchronise the 50 heart rate of the house current and only then are allowed to supply current. Conversely, this means that the current produced by the micro inverter is cut off at such a high speed as soon as a fuse blows or a power failure interrupts the current that there is normally no danger to the user. Furthermore, microinverters must be treated like other commercially available small electrical appliances and the safety instructions and precautions specific to the device must be observed in order to avoid personal injury.

This information from Plug Solar is provided to the best of our knowledge and belief, but without any legal guarantee or warranty. You are welcome to obtain additional information on the Internet or from other specialist companies in order to find the right solution for you.