The craze for electricity from the balcony: Is it worth it?

In Germany, there is a real craze for solar modules that are installed on the balcony or some other suitable place. According to data from the Federal Network Agency, in the first quarter of this year the number of such mini-plants reported increased seven times compared to the same period last year. “The market is huge, 12 million such mini-plants could be installed in Germany by 2030,” solar module expert Christian Offenheusle estimates for DW. He is the initiator of the MachDeinenStrom.de website, where interested parties can find out if the trend continues, in seven years every fourth apartment in Germany could have such a solar mini-plant. And in China, small solar plants are becoming more and more popular. In the million-strong metropolis of Hangzhou, for example, they are often installed on large residential buildings where apartments are rented, says Hans-Josef Fell from the company “Energy Watch Group”. In Italy, the largest electricity supplier there, “Enel”, propagates this type of electricity production for its own needs. Offenhäusle has also noticed a great interest in this technique, which is easy to install, in other European countries – in Poland, France, the Netherlands, Great Britain, and Austria. , Switzerland and Hungary. How do the solar modules for the socket work? Small solar plants usually have one to three solar panels. They are attached to the balcony, to the wall of the house, to the terrace, somewhere in the garden or on the roof. They can also be used by those who rent an apartment, but in order to install them, they must ask for the landlord’s permission. Small solar plants or, more precisely, devices for generating electricity, can be installed by a person himself, without the help of an electrician or any other craftsman. The direct current generated in the solar module is conducted to the box, that is, the inverter, where it is converted into alternating current, and then it is introduced into the home network via an ordinary plug in the wall. As a rule, the electricity produced by the solar device is consumed in the household, but the surplus can also go to the public grid. How much electricity does the solar module for the balcony produce? The amount of electricity produced depends on the strength of the sun in a certain area and the direction of the solar panels. In Africa, the Middle East, Australia, parts of China, Latin America and the USA, a 400 watt solar module can produce up to 800 kilowatt hours of electricity in a year. In Germany and elsewhere in central Europe, the amount of electricity produced is roughly half that. It is optimal to turn the module to the south and at a certain angle, so that the sun’s rays fall as directly as possible on the solar panel. If it is not possible to place the module at a certain angle, the amount of current produced will be less. If the 400 watt module is placed in the best possible way – on the wall or balcony railing on the south side – it is possible to produce about 260 kilowatt hours in Germany in a year. If it faces east or west, then about 190 kilowatt hours. Is the balcony module sufficient for household needs? In developed countries, electricity consumption is high. A household with four people in Germany consumes about 4,000 kilowatt hours of electricity per year, a household with two people about 1,500 kilowatt hours. A well-aimed 400-watt solar module can produce about 320 watts during the spring and summer, half that if it’s partly cloudy, and only about 50 watts if it’s very cloudy. In autumn and winter, if it is clear, such a module can produce about 160 watts, and if it is very cloudy, only about 20 watts. This means that the balcony module covers only a small part of the household’s electricity needs. How much does a balcony solar plant cost? A small balcony solar plant with one to three modules costs between 400 and 1,200 euros in Germany. If the price of electricity is between 30 and 50 cents per kilowatt hour, the procurement costs are amortized in six to nine years, estimates Thomas Zeltman from the Association for the Solar Economy in Berlin. After that, according to his calculation, the electricity produced by the balcony solar plant would be free for at least another ten years. Because solar modules usually have a shelf life of about 25 years, and the circuit for converting direct current into alternating current about 15 years. Are balcony solar modules safe? “In principle, balcony solar devices are very safe, so far no damage is known,” says Zeltman. However, he recommends that such devices be purchased only in specialized stores or from specialized providers on the Internet. Their components are adapted to each other, and can and help during installation, if necessary. The installation of balcony solar plants is allowed in more and more countries. In the European Union, it is allowed in 25 of the 27 member countries. Only in Belgium and Hungary are balcony solar devices not allowed for now.