Do you want to save energy and reduce your electricity costs in the long term? Small systems for balconies and house walls can simply be attached to the socket. How good are the mini power plants?
Plug in and the electricity is already flowing: Solar power systems for balconies, garden sheds, carports and house and garage walls can be operated that easily. Such compact photovoltaic systems with plugs for ordinary sockets are not only the first step for homeowners to produce their own electricity, but also for tenants.
“The appeal of these devices is that they can be easily set up and operated by non-professionals,” says Martin Brandis, energy consultant at the Federal Association of Consumer Organizations. The descriptions supplied by the manufacturer are usually sufficient for this, and support from a specialist company is usually not required.
How do the facilities work?
An essential element of these off-the-shelf solar systems are one or two panels that together generate a maximum output of 600 watts. Direct current is generated by solar radiation, which is then converted to mains current in the device. And it goes into the domestic power supply via a standard Schuko plug.
To be on the safe side, you should make sure when buying that the model you choose can actually be connected to standard house sockets. Otherwise there is a risk of overloading and, in the worst case, a fire. There are also models that provide a special power socket.
The big advantage: The panels can not only be installed quickly via the sockets, they can also be dismantled quickly and you can take them with you. And that’s why they are just as suitable for tenants as they are for house and apartment owners.
Are there special conditions for tenants?
You should ask the homeowner for his approval before starting construction, recommends lawyer Julia Wagner from the Haus & Grund Germany owners’ association. This is because he is responsible for ensuring that his property supports this system safely and that neighbors are not adversely affected by glare or shading.
Where can I hang these photovoltaic systems?
The systems need an area on or near the building, for example on a balcony. “In order to make optimal use of the incident solar radiation, the panels should be aligned to the south,” advises energy expert Brandis. The inclination of the solar modules also plays a role for maximum electricity yield. “Between 20 and 30 degrees inclination is optimal.”
Slight deviations from these specifications, for example because the systems are moved to avoid the shadows of neighboring buildings or trees, are not of great consequence. Even vertical mounting on the facade is possible.
What do the systems cost?
The devices, also known as balcony power plants, cost between 400 and 800 euros, depending on the configuration. “They are mainly sold via online shops, and you rarely see them in DIY stores,” reports Martin Brandis.
Extra costs may arise, for example if there is no Schuko socket nearby or if the selected models require special power sockets. Where they are missing, they must be fitted and connected by a specialist company.
In addition, the grid operators expect a two-way electricity meter so that the solar power that is not consumed directly in the household can be forwarded to the general power grid without any problems. The purchase and installation costs of these devices are borne by the network operator, but the end consumer has to pay a monthly or annual rent for the meter.
Good to know: The systems are largely maintenance-free and designed for a good 20-year service life.
How much electricity can I produce with it?
“A solar plug-in system generates an average of up to 600 kilowatt hours (kWh) of electricity per year,” says Bernhard Weyres-Borchert from the German Society for Solar Energy (DGS). “It should be noted that the yield can also be significantly lower depending on the location and local conditions.”
With an average annual electricity consumption of around 1200 kilowatt hours (kWh) per person, the potential is manageable. In addition, the system generates most of the electricity from solar energy in the summer, while the yield is likely to remain low in the winter.
Do the systems contribute to the energy transition?
Every little bit of electricity from sustainable energies does that. Even if experts like Martin Brandis and Bernhard Weyres-Borchert say that the heyday of plug-in solar devices off the shelf is still to come. “These concepts do not yet play a major role in the energy transition. However, if they become more widespread, especially in densely populated metropolitan areas with many rental apartments, their importance could increase,” says Brandis.
Surf tip: Solar system on your own roof? You can also rent one.