June 17, 2025, 4:35 am | Read time: 3 minutes
In times of the energy transition, solar power systems for balconies are becoming increasingly popular. However, caution is advised when purchasing the components. The inverter, in particular, could be faulty.
With balcony solar systems–also known as “balcony power plants”–you can harness solar energy for your own household. These devices are becoming increasingly popular and are also an option for renters. However, there are several factors to consider when purchasing and installing them. The Federal Network Agency has now warned about defective electrical components for balcony solar systems. Unfortunately, there are numerous inverters for balcony solar systems in both brick-and-mortar and online retail that are unauthorized or potentially dangerous, said agency president Klaus Müller, according to a statement.
Defects in Inverters for Balcony Solar Systems
The agency noticed solar inverters that lacked a CE mark, a German user manual, or a German dealer address, which is not allowed. Other devices showed defects in metrological tests and, for example, exceeded legal limits for electromagnetic compatibility.
Update from August 8, 2023: The colleagues at Computer BILD (like myHOMEBOOK, part of Axel Springer SE) discovered a potentially life-threatening flaw in an inverter in their test lab. It concerns the “MIC 600TIL-X” inverter from the Chinese manufacturer Growatt, specifically made for balcony power plants. It was found that the automatic shutdown, which should activate during a power outage, reacts too slowly (0.9 seconds instead of 0.2 seconds). Additionally, the inverter increases the alternating voltage from 230 volts to up to 460 volts. If you unplug the inverter and touch the contact within this period, you can get an electric shock. Even at 50 volts, it can be life-threatening. Other devices in the power grid can also be damaged.
More on this: When a solar system on the balcony is worthwhile
How Do Inverters Work?
Inverters convert the direct current produced by balcony solar systems into alternating current. In the simplest case, you only need to plug a connector into an existing socket. The electricity from the solar device then flows to the electrical appliances. In return, less electricity is drawn from the grid. These systems are known as balcony power plants or plug-in solar modules.
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What Should You Consider When Buying?
The agency recommended that consumers purchase from reputable and well-known sources when ordering online and seek information from consumer centers beforehand. Customers should also ensure that the plug type is usable in Germany.
These are signs of reputable products: An address in the EU where the provider or their partner can be reached, the CE mark, information on general terms and conditions (GTC), as well as cancellation and return policies. The availability of a German-language user manual is as important as an inverter plug type suitable for Germany.
A price that is too low should raise suspicion. If you are unsure, you should ask the provider specific questions about the product, according to the Federal Network Agency. Reputable sellers usually respond quickly and willingly.
with material from dpa