August 17, 2023, 3:48 pm | Read time: 9 minutes

With a solar panel on the balcony, you can supply your household with electricity—at least partially. This sustainable energy solution isn’t just for homeowners. Renters can also install smaller systems on their balconies.

How do balcony solar systems work?

Balcony solar systems typically consist of two modules and an inverter, with a capacity of up to 600 watts. The devices can be easily set up and usually feed their energy only into the house network. They require little space and are attached to the balcony railing, or they hang on the garden shed, carport, or house and garage walls.

While the mini-systems function like the large systems on the roof, they are technically more like electricity-generating household appliances. These solutions, also offered as mini-solar systems or plug-and-play systems, can be easily dismantled, making them attractive for renters who might move.

Also interesting: What to look for in solar system offers

How do you register the systems?

Until now, private households had to register the solar systems themselves with the energy supplier. This is set to change: The draft law from the federal cabinet aims to reduce bureaucracy in 2024. In the future, the system will no longer need to be registered with the grid operator, and the entry in the market master data register will be limited to a few data points. Currently, there is still some effort involved: In addition to the entry in the register for the German electricity and gas market, you must contact your grid operator.

These formalities and the requirements for operators are currently not uniformly regulated nationwide. “With the registration with the grid operator, for example, proof may be required that a special feed-in socket, the so-called Wieland socket, is used,” says Jörg Sutter from the German Society for Solar Energy (DGS). “Additionally, customers must assure some grid operators that their system was installed by an electrician.”

Important Note: According to the Low Voltage Connection Ordinance, only an electrician may work on the public electrical supply network. “However, no one will hold you accountable if you do it yourself,” explains Melanie Unseld from the Association for Electrical, Electronic & Information Technologies (VDE) upon request from myHOMEBOOK. But be careful: Home and building insurance will not pay if a house fire or even personal injury occurs.

When is a regular Schuko socket sufficient?

For a standard-compliant connection, the VDE currently recommends the special feed-in socket, such as the Wieland socket. However, there are efforts to relax these recommendations, and the German Commission for Electrical, Electronic & Information Technologies (DKE) is currently revising a corresponding standard. The Schuko plug and its counterpart, the Schuko socket, are the usual connections in Germany–almost everything in our household is connected to the grid with them.

“In principle, plug-in solar systems can simply be connected to a Schuko socket if the technical safety standards according to the upcoming product standard are met,” says Alexander Nollau, head of department at the Association for Electrical, Electronic & Information Technologies (VDE). “In a modern house installation, this should be possible without problems. With old installations, I would be cautious and have an electrician install the balcony system.”

Do I need a new electricity meter?

The legal amendment provides that future balcony systems may temporarily operate behind any existing meter type. This also includes meters without a backstop. These devices run backward when more energy is fed into the public power grid than is consumed–which is currently prohibited and requires a meter exchange.

However, the backward-running meters, as well as normal single-phase meters with a backstop, will only be tolerated until the metering point operators install modern two-way meters. It may be advisable to inquire with the local authority.

Full feed-in or compensation?

Since January 1, 2023, new compensation rates for solar systems have been in effect, according to the Consumer Center–including those on the balcony. Households that generate electricity for self-supply through the systems receive higher compensation rates. Specifically, this means that operators of a photovoltaic system with a capacity of 10 kilowatt-peak (kWp) receive about 8.2 cents per kWh.

In contrast, for a full feed-in of electricity, systems up to 10 kWp receive about 13 cents per kWh. Whether you want to fully or partially feed in the generated electricity can be determined annually. The yield calculator from Stiftung Warentest can help with the decision. Since the beginning of the year, producers are no longer limited to feeding only 70 percent of the generated electricity into the grid but can feed in more. However, this only applies to systems with a capacity of up to 7 kWp.

While it is possible, as with large solar systems, to feed electricity into the public power grid if a two-way meter is present and the plug-in PV system is registered with the Federal Network Agency and the local grid operator, the amount of electricity fed in is likely to be very small. Such systems are therefore more suitable for self-consumption.

“However, an electrical specialist should first check whether the line is designed for power feed-in if the mini-PV system is to be connected to an existing power circuit,” advises Melanie Unseld from the VDE upon request from myHOMEBOOK. In some cases, you may need to replace it beforehand to prevent overload.

What does a balcony power plant cost?

According to the Consumer Center, the cost for devices with a standard module ranges from 350 to 600 euros. At the beginning of the year, the value-added tax on these products was eliminated. Additionally, many municipalities, districts, individual federal states, and regional associations offer subsidies. According to the German Association of Towns and Municipalities (DStGB), interested parties should be able to find this information on the respective website of their municipality, city, or district. The respective environmental offices or climate protection departments are responsible, among others.

Note: To use your own solar power even in bad weather, a storage battery is necessary. Unfortunately, solar storage systems are still very expensive, costing several thousand euros, unlike balcony solar modules.

More on this: Balcony power plants–the best mini-solar systems in comparison

How much electricity does the balcony solar system generate?

A standard module with 400 watts of power can produce about 280 kilowatt-hours of electricity per year in a shadow-free location on a south-facing balcony, according to the Consumer Center. That’s not much: A two-person household can, for example, run a refrigerator or washing machine for a year. Or save 85 euros annually–if you don’t have to buy energy from the public grid at a price of 35 cents. At shadier locations, electricity production decreases. Therefore, it is generally advised to orient solar systems to the south, southeast, or southwest.

VDE spokesperson Unseld conducted a sample calculation for myHOMEBOOK: “Mini-PV modules have a power output of 150 to 300 watts under test conditions. On average, an output of 70 to 85 kilowatt-hours per 100 watts of nominal power is expected per year. A 500-watt system, for example, generates around 350 to 425 kilowatt-hours per year. A four-person household requires about 3,000 kilowatt-hours of energy per year. Conclusion: A four-person household could draw over ten percent less electricity from the grid operator.”

When has the balcony solar system paid off?

When a mini-solar system has paid for itself depends largely on how much electricity it generates. Several factors play a role here:

• In which direction is the mini-solar system oriented?
• Is the angle of incidence of the sun optimal?
• Is there any shadow on the solar modules?

“In a period of two to three years, the energy expenditure required for production is already amortized,” says Unseld. The purchase costs for a mini-solar module are offset by the saved electricity costs after eight to 15 years, according to the expert.

According to Jörg Sutter, vice president of the DGS, most users are not so concerned about the point at which it pays off: “Much more relevant is that plug-in solar offers a way to participate in the energy transition with little money and to generate electricity in an environmentally friendly way.”

Where can you get solar modules for the balcony?

The modules can be easily purchased at hardware stores or ordered online. Before buying, consumers should inform themselves thoroughly. Energy expert Unseld warns: “There are many different systems available on the market, unfortunately, still some where the customer has to tinker themselves and only a cable comes out of the inverter.” However, the vast majority of manufacturers offer so-called energy plug devices. These include a plug plus socket that avoids direct contact with voltages. “The customer does not get an electric shock and cannot touch an active conductor.”

Handy individuals can install the solar modules on the balcony themselves. The complete sets usually include a module, wiring, an inverter, and a substructure. “If you don’t trust yourself to do your own installation, you can ask an electrician or solar company and also buy such a small system fully installed, including assembly and connection,” explains Jörg Sutter upon request from myHOMEBOOK. “You must ensure that the installation site is as sunny as possible and that the ground is stable enough to securely fasten the module even in a storm,” advises the physicist. In rental apartments or a condominium association, landlords or co-owners must be consulted. Depending on the contract, their approval must be obtained.

Another tip: The DGS offers a large product overview of plug-in solar modules on its website, which can also be filtered by performance or price. The cheapest models are available from around 350 euros.

Related: Is a solar system actually worth it in winter?

More on the topic

Mini Solar Systems Important Update for Balcony Power Plants: Electricity Meters Can Run Backward

Solar Package Approved What Renters and Owners Should Know About Balcony Power Plants

Also for Renters Agreement Reached on Solar Package! Key Changes for Balcony Power Plants

What should renters consider?

Before installation on a balcony, the landlord must be asked for permission, according to the Hamburg Tenants’ Association. The corresponding approval should be in writing. According to the Consumer Center, the homeowners’ association must also agree.

with material from dpa