Balcony power plant: mini solar systems for the socket
We will inform you about everything important you need to consider in connection with the mini solar systems for balconies and gardens
What is a balcony power plant and how does it work?
Solar systems are becoming increasingly popular. But tenants and apartment owners in particular cannot have a system mounted on the roof without any problems. A balcony power plant is particularly interesting for them. This is a mini solar system that is connected to the power grid by means of a plug. It consists of up to four solar panels that can be attached to the balcony, terrace or façade. The direct current generated is converted into alternating current via an inverter, as in a conventional PV system. You can use the electrical energy generated directly for your own electricity needs.
What is the difference between a balcony power plant and a classic photovoltaic system?
In terms of how the solar cells work, plug-in solar systems do not differ from their more powerful counterparts for the roof or other large areas. They are virtually the mini version of a classic photovoltaic system. In contrast to this, however, a balcony power plant is connected to the already existing end circuit of the house or apartment. This makes it an energy-saving and environmentally friendly tool that can also be used by smaller households without any problems. The mini solar systems are mostly used on balconies, terraces or in the garden.
Under what conditions are balcony power plants allowed in Germany?
Since 2018, German households have been allowed to install PV balcony modules without a permit. The legal requirements for this are laid down in the pre-standard DIN VDE V 0100-551-1 of the Association of German Electrical Engineers. Among other things, this states that the integration of the PV system into an existing circuit must not be carried out via an ordinary household socket. Instead, a special energy socket is required. However, the VDE and the Federal Network Agency are currently discussing the revision of the existing standard to facilitate installation. It is therefore quite possible that the use of an ordinary Schuko plug for the mini PV system will soon be permitted. Nevertheless, the now mandatory commissioning of specialist personnel for the installation remains recommended.
The Federal Government's goal is to make it easier to use balcony power plants. In its photovoltaic strategy, it says the following: "Citizens should be able to connect and commission the systems themselves, without the help of skilled workers."
The background to this goal is the veritable "PV boom" that has been taking place for some time. As a result, the number of requests for grid connection to the low-voltage grid increases sharply. So much so that installers and network operators can no longer keep up. After all, human resources are limited. For this reason, a standardised, digital process for grid connections is to be created.
If you use a mini solar system, you are obliged to record the solar power generated. Waiving a bidirectional meter can have criminal and tax consequences. In the future, the federal government would like to tolerate backward-turning meters, at least temporarily. And this will continue until the meter is replaced.
Even before the meter is replaced, it is intended to enable the operation of a plug-in solar device. This means that the meter replacement is not obsolete, but at least the mini solar system can be connected immediately.
This special meter can be rented through the electricity provider. Accordingly, they are an important point of contact if you decide to install a balcony power plant. But here, too, there is hope for relief: The VDE demands that in the future it should no longer be necessary to change meters for the use of a balcony power plant. If the subsidy passes, old meters that run backwards when fed into the grid would also be permitted.
By the way: In the following video, the influencer and expert for e-mobility Robin Schmid also explains what you need to know about mini PV systems:
How is a balcony power plant installed?
In order to ensure the flawless and safe functionality of a balcony power plant, a standardised socket is required. A connection via a standard household safety contact socket (Schuko for short) is not yet permitted. The same applies to classic multi-distributor sockets. After the common socket has been replaced by trained specialists, the mini PV system can be connected to it and put into operation.
The government now wants to change this and also allow the Schuko plug as a possible energy plug. This measure is then also to be regulated in the product standard DIN VDE V 0126-95.
The background to this rethinking is the fact that the risk of electric shock in a mini solar system is roughly comparable to that of other conventional household appliances. In addition, the risk of fire when using wall sockets is rather low, provided that the Schuko plug is combined with an appropriate module inverter with system and grid protection.
The legal prerequisite for the commissioning of a balcony power plant is a bidirectional meter with a backstop.
How big can a balcony power plant be without a permit?
A balcony power plant can consist of up to four solar modules – but in terms of space, most people use 1-2 modules. It is important that the power from the inverter must be reduced to 600 watts. This is also currently being discussed. The federal government's plan is to increase the current threshold of 600 W. In the meantime, the BMWK has submitted a request to the standardiser (VDE/DKE/FNN) to increase this limit to an alternating current output of 800 VA.
According to the EU regulation "Requirements for Generators", generation plants with an alternating current output of less than 800 W are not important. It is up to the member states to set an upper limit, as long as it does not exceed 800 W.
The decisive factor is whether the yield of a plant is considered "grid-relevant". This is the case in Germany at 600 watts, but the EU sees the limit at 800 watts. It is quite possible that you will soon be able to generate a higher yield. Even now, your mini PV system can generate more than 600 watts in order to be able to generate enough electricity even on days with little sun. However, the actual feed-in is limited by the inverter.
Is only a qualified electrician allowed to take over the connection?
According to the specifications, a qualified electrician must always check whether the cable is sufficiently dimensioned for the feed-in, if an existing circuit is to be used. Photovoltaic systems of any size should always be connected by a specialist electrical company. This is also our urgent recommendation. The Federal Network Agency provides information about an exception on its official website: "However, up to an output of 600 watts and if the special socket and meter are available, this regulation has now been changed so that consumers can also connect the system themselves and register it with the grid operator. In some cases, the network operators provide their own forms for this purpose."
When and where do I have to register a balcony power plant?
In general, a balcony power plant must be registered with both the Federal Network Agency and the respective grid operator when it is commissioned. The basis for this is the Low-Voltage Connection Ordinance and the VDE application rule "Generation plants on the low-voltage grid". The corresponding data is stored in the market master data register. Registration is at no additional cost. An annual reporting obligation for mini solar systems that have an output of less than one kilowatt hour and are used exclusively for self-sufficiency will no longer apply. Due to the restriction of inverters, balcony power plants usually fall below the de minimis limit of 600 watts anyway.
Either way, relief is likely to be imminent here as well. In the future, the German government would like to simplify or even eliminate the current reporting obligations. Mini-PV systems currently not only have to be entered in the market master data register, but also reported to the grid operator. The aim is to simplify this "double reporting".
Reduce electricity bill
The advantage of a balcony power plant: The electricity is fed directly into the house's own circuit. The electricity provider only has to provide the difference to the actual energy consumption. The end result for you is a lower annual electricity bill.
Is it worth buying a mini PV system?
The purchase of one or more balcony PV modules can not only make sense from an environmental point of view, but also ensure that your wallet is spared. Basically, the power limit of a permit-free mini solar system for the socket is 600 watts. In most cases, the modules are offered with 300 watts.
By comparison, the energy requirement in a typical German single-family household is covered by about 270 kWh by a balcony power plant with an output of about 300 watts. On average, the following are needed in total:
| Persons | Approximate annual electricity consumption |
|---|---|
| 1 person | approx. 2,000 kWh |
| 2 persons | approx. 3,000 kWh |
| 3 to 5 people | approx. 4,000 to 5,900 kWh |
Depending on the size of the household, the savings in this case are up to 15 percent compared to conventionally supplied electricity.
Whether a balcony power plant is worthwhile also depends on many factors, such as regional solar radiation, your personal daily rhythm and the orientation of the mini solar system. As a rule, balcony power plants are supposed to cap the energy consumption in the household up to a certain level. In principle, it is also possible to feed electricity into the public grid. However, the actual remuneration is usually very low and disproportionate to the effort.
With solar systems, it is common to use an electricity storage system to collect excess energy and use it later instead of feeding it into the public power grid. A balcony power plant with a storage system only makes sense if the storage system is already integrated as a complete set. With retrofit solutions, the costs for the storage system quickly turn out to be higher than for the solar modules themselves. Even with rising electricity prices, the acquisition costs are so high that a balcony power plant with storage quickly becomes unattractive.
How much does your own balcony solar system cost?
The balcony power plant price is primarily based on individual needs: the more power is desired, the deeper consumers have to dig into their pockets. The costs for a complete package consisting of a solar module and inverter range between 300 and 1,000 euros on average. In addition, there are expenses for the installation of the balcony power plant and the use of the electrician. If you add up all the items incurred, the total costs for the purchase of a balcony power plant are approximately 1,500 euros. However, these pay for themselves after just a few years.
Are balcony power plants subsidized?
Balcony power plant subsidies, on the other hand, have so far only been available regionally, depending on the output and number of solar modules. However, the federal government has abolished VAT on solar systems as an incentive to buy, which also benefits balcony power plants. Thus, the 19% is attributable to the purchase price – provided that the seller passes on the savings.
With a balcony power plant, you not only make a contribution to environmental protection, but also save money at the end of the year.
Are tenants allowed to install a mini-PV system?
The basic prerequisite for installing a mini PV system is sufficient space on the balcony or terrace: solar cells of a system with 300 watts of power require just under 1.7 m². With an output of 600 watts, you need 3 m² of space. As is the case in many other situations, tenants must also coordinate their plan for installing a balcony power plant with the homeowner or landlord in advance. Often, the rental agreement also regulates the installation of a mini solar system. This is because in order to lay cables or install the solar modules, some changes have to be made to the building fabric, such as drilling through walls or balcony balustrades. If approved, nothing stands in the way of environmentally friendly self-sufficiency. If the decision is rejected, tenants have to accept this decision. An owner can also prohibit the installation of a mini PV system under certain circumstances.
In the future, Steckersolar is to be included in the existing "catalogue of privileged measures" in the German Civil Code (BGB) and in the WEG (Condominium Act).
Until now, landlords or homeowners' associations have had to approve the operation of plug-in solar devices. If this is now included in the catalogue of privileged measures, tenants and owners are automatically entitled to such a permit.
The residents of an apartment building must coordinate with the landlord in advance regarding the installation of a balcony power plant.
