Solar energy from your own balcony – how much it costs and what it yields

Installations of solar panels on the roofs of commercial buildings and single-family homes are booming – driven by high and rising energy prices. Demand was already increasing before the war in Ukraine and the associated price explosion.

In 2021, for example, new photovoltaic installations in Switzerland increased by 43 percent year-on-year to a new record of 683 megawatts. This is what the Bundesamt für Energie writes in its solar energy statistics for 2021.

What few people know: you don’t always need a large installation and a large wallet. There is another way.

Not only homeowners, but also tenants can take care of their own solar system at manageable costs. The keywords are “balcony power station” or “plug & pay system”.

These are ready-to-use small photovoltaic systems that can be attached to balcony railings, for example, and connected to the socket without specialist knowledge. With the help of an inverter, the solar energy is converted into normal household electricity. Completely.

Depending on the supplier and model, the mini photovoltaic systems consist of one or two solar panels connected to an inverter. This converts the direct current generated by solar energy into alternating current, which is supplied to the electricity grid via a plug. The electricity can therefore be used immediately.

In particular, household appliances, such as refrigerators, internet boxes or televisions that are in standby mode, which are always on, are not primarily powered by the conventional circuit, but by self-generated solar energy. This means that these devices can be operated “free”.

Unlike conventional photovoltaic systems, “Plug & Play” systems do not require large areas on house roofs. A balcony screen, a gazebo or a privacy screen is sufficient to fix the consciously light solar panels with tension straps or cable ties. Tenants can easily dismantle the installations themselves when they move and use them again in their new home.

Since the “balcony power plant” is only connected to the house’s power supply via a socket, no electrician has to be called in for commissioning – unlike large photovoltaic systems.

Yes. In Switzerland, ready-made “Plug & Play” solar systems with the required protection devices up to a power of 600 watts can be installed and operated without a permit. The Federal Inspection for Heavy Current Installations ESTI confirmed this in a bulletin in 2014.

However, the electricity grid operator must be notified in writing before the system is commissioned. AEW Energie AG has forms available for this on its website in Aargau. A maximum of one installation may be operated per meter circuit or apartment.

And: If the panels are mounted outside the balcony hole or directly on the facade, permission from the landlord is required.

With a power of 600 watts, “balcony power plants” are not very productive, so most of the electricity is consumed directly by appliances in the home. The electricity that is not used flows into the general electricity grid and is used elsewhere, increasing the share of ‘green electricity’.

In principle, a feed-in tariff for the return of solar energy is also conceivable for “Plug & Play” systems. For this, the network operator must be asked whether a bifunctional electricity meter is present and whether there is a feed-in tariff.

The provider solarbalkon.ch has carried out a sample calculation on its website for a “Plug & Play” system, in which the concrete savings depend on the one hand on the electricity production and on the other hand on the energy costs to be paid at that time.

In the calculation example with a south-facing, slightly inclined system in a sunny location, the company assumes electricity production of 600 kilowatt hours per year. At an estimated base rate of 33.84 centimes per kilowatt hour, this saves 203 francs per year.

If you divide the estimated initial cost of CHF 1,000 (prices vary depending on the provider and model) by this amount, you can assume a useful life of about five years before the system is depreciated.

The plug-in solar simulator HTW Berlin offers a more accurate calculation. Factors such as orientation and electricity costs can be entered there to compare the advantages and disadvantages of smaller and larger systems.

Since more and more households in the canton of Aargau are also interested in “Plug & Play” solar systems, the energy supplier AEW Energie AG has now published a fact sheet on mini solar power plants.