Heidelberg. Mini solar systems are becoming cheaper and cheaper. Ideally, the acquisition costs have now been amortized after just three years. The balcony power plants are particularly popular in northern Germany, but they are not very common in large cities. This was the result of an evaluation by the comparison portal Verivox.
Mini solar system reduces electricity bills by up to 228 euros per year
Plug-in mini solar systems consist of one or more modules that can be attached to the balcony railing, the house facade or the roof, for example, or set up in the garden.
Under ideal conditions, a balcony power plant with an output of 600 watts can supply around 570 kilowatt hours (kWh) of electricity annually. If you use all of the electricity yourself, this corresponds to savings of around 228 euros per year at an average kilowatt hour price of 39.94 cents/kWh.
A balcony solar system of this size costs between 700 and 900 euros. In this sample calculation, the acquisition costs are included again after three to four years. If the system runs for 20 years, around 4,550 euros in electricity costs are saved.
“Balcony power plants have become cheaper and cheaper in recent years. That’s why they pay for themselves more and more quickly. This year there will also be no VAT on purchases. Some federal states and many municipalities are also promoting the purchase,” says Thorsten Storck, energy expert at Verivox.
Right place for the balcony power station is important
The location is decisive for the yield of the system. The best yield of solar energy is achieved when the balcony faces south, the modules are installed at a slight angle and no shadow falls on the solar modules. However, if you have a north-facing balcony and can only attach the modules vertically, you will receive less than a third of the possible yield.
“The systems are often worthwhile even if ideal conditions are not achieved, for example because the alignment is not optimal or self-consumption is lower. It just takes a little longer then,” says Thorsten Storck.
Technical requirements for the balcony solar system
The providers of balcony solar systems advertise that the devices can be set up directly and connected to a conventional socket. The Association of Electrical Engineering (VDE) recommends special feed sockets, which can be installed without much effort. In addition, it must be checked beforehand whether the current electricity meter is suitable for the operation of a balcony solar system.
As part of Solar Package I, the federal government wants to simplify the purchase of mini solar systems. The limit for mini solar systems is to be increased from 600 watts to 800 watts and the use of normal Schuko plugs is to become the norm. It should also be tolerated that older Ferraris electricity meters sometimes turn backwards when the mini solar system is fed in. In addition, the registration of the systems is to be made easier – so far this has to be done both with the local network operator and with the Federal Network Agency.
State funding works: balcony power plants are particularly popular in northern Germany
In 2023 alone, around 148,000 of the around 220,000 mini solar systems registered in the Federal Network Agency’s market master data register were registered. There is also an unknown number of unregistered devices.
Most balcony power plants were registered in the first half of 2023 in the most populous federal states of North Rhine-Westphalia (31,346) and Bavaria (22,919). However, most registrations per household were in northern Germany: 5,584 mini solar systems were registered in Mecklenburg-Western Pomerania, which corresponds to around 0.7 percent of households, and in Schleswig-Holstein there were 8,817 devices (0.6 percent of households). In both federal states, the purchase of a balcony power plant is funded – in Mecklenburg-Western Pomerania with 500 euros (now only for tenants), in Schleswig-Holstein with 200 euros.
In the city states of Berlin and Hamburg, the proportion of registered balcony power plants per household will be the lowest at around 0.1 percent in 2023. In Berlin, too, the purchase of a mini solar system is subsidized with 500 euros, but only tenants are entitled and the application must be made before the purchase.
methodology
The number of registered devices was calculated using the market master data register charged by the Federal Network Agency. Among other things, all power generation systems are registered there, including mini solar systems. The average electricity price corresponds to the Verivox consumer price index for electricity in July 2023.