Operate two balcony power plants or more

Operate two balcony power plants or several balcony power plants:

We are often asked whether it is legal to operate two or more balcony power plants in one house. Or a satisfied user would like to expand their existing balcony power plant with solar modules.

To clear up the confusion here is the following article. Please note that our contributions are informational in nature. In individual cases, legal advice or your electrician should be consulted.

Two or more solar modules to one inverter:

In principle, more than two solar modules may be connected to operate a balcony power plant . The decisive factor is the fed-in power of 600 watts. This is controlled by the inverter anyway. The panels can therefore generate more than 600 watts. It is particularly important to emphasize here that modules with higher output, for example 800 watts, generate significantly more energy, especially when it is cloudy or in winter, compared to solar modules with less output.

However, when operating several solar modules, the permissible power should be taken into account. Microinverters tend to be designed for one to two modules. The permissible input power for your inverter can be found in the inverter data sheet. Over-occupying an inverter, for example with three solar modules instead of two, can lead to overvoltage. What often works in the winter months or when it is very cloudy can lead to defects in the inverter in spring and summer. Mandatory loss of warranty. We strongly advise against this.

Two inverters/balcony power plants or more on one circuit:

According to the VDE, two inverters that are connected to a circuit with a separate connection cable are taboo. An example is two inverters with separate cables connected to two sockets on the same meter circuit.

In a balcony power plant, the power fed in per circuit/meter must not exceed the 600 watt limit. (The limit will probably be raised to 800 watts on January 1st, 2024)

We would still like to show the technology of how microinverters can be coupled to operate more than one balcony power plant. Most modern houses offer the infrastructure so that the electricity produced by two balcony power plants can be easily processed. It is important to mention again here that this is not permitted according to the VDE and the network operator. If you operate several balcony power plants, your system is no longer a small generation system with simplified registration, but a standard photovoltaic system . Please have your electrician check the cables. It is advantageous for us to have a separate feed directly into the meter cabinet, with our own protection, if necessary also via a cable with a larger wire cross-section, e.g. 2.5mm² and more.

The setup:

In order not to have to connect each balcony power station to individual sockets and "waste" your sockets, identical inverters can be coupled. With common models (e.g. Hoymiles, Envertech, Deye) the connection is made directly with the Betteri plug or suitable adapter cables. The connection is direct in AC (alternating current), so that the "finished" alternating current from one inverter is only carried out by the second inverter. The last inverter is finally connected to the house network.