Checklist & information for installing a balcony power plant (BKW) in an apartment building in Vienna
Sometimes, when interested parties contact us, it's about a very specific topic: the balcony power plant, or BKW for short. And because this has been happening more frequently lately, we'd like to tell a little story here – namely that of Initiator and founder of the EEG Wienerberg, Andreas GrafIt begins with a conversation between him and his lawyer – and continues with a wealth of research, experiences, and learnings that might also be helpful for you.
The idea was simple: to have your own balcony power plant, mounted in a Apartment buildingBut it soon became clear that it wasn't that simple.
The first step, Andreas learned, was to Property management, i.e. the owner representative, to inform. Without their consent, nothing can be done. However, this consent cannot be arbitrarily withheld. A simple "We don't like it" is no longer sufficient. Balcony power plants enjoy legal priority, and an objection by the property management must be precisely justified. Nevertheless, in practice, there will often be certain conditions. This was also the case with Andreas. The management demanded Evidence of fall protection and wanted to make sure that the BKW no damage to the building would arise.
It was therefore quickly decided that the power plant should installed by a specialist company Self-installation is permitted, but it carries with it a certain amount of responsibility. In such a case, it would be necessary to consult an expert to confirm safety. Therefore, the best option is to purchase a complete package—module, inverter, storage, and professional installation—from a single source.
However, this decision also made it clear that the project significantly more expensive It would be more challenging than initially thought. And it wasn't just about the construction issues. The basic suitability of the balcony also had to be examined. Does one even have enough sun? Andreas decided to find out for himself – with a pyrometer He took over several days Measurements Particularly exciting is the so-called bifacial techniqueIt also measures the light that hits the back of the solar panels. This can be particularly worthwhile in taller residential buildings, where a lot of light is reflected from the facades.
The next point was the question of electricity consumption. The electricity from the BKW can only be used when the sun is shining. Anyone who does not use the generated electricity directly needs a memoryAndreas discovered models like the "Noah 2000" from Growatt and the "Solix Solarbank" from Anker. However, prices are still high. A 2 kWh storage unit costs around €700 to €900.
But that’s not all: the in-house Electrical system must be suitableAnd sometimes an official electrician's report is necessary to confirm this.
One thing must not be exceeded in Austria under any circumstances: The Feed-in power of 800 wattsThe inverter is therefore allowed to deliver this maximum power. The modules, however, can certainly deliver more power—for example, three panels with a total of 1500 watts—as long as the inverter complies with the limit.
After all these questions had been clarified, the next step came: the Registration with Wiener NetzeThis is done easily online. You'll receive a confirmation email, and from that moment, Wiener Netze has 14 days to object. If no objection is received, the process can begin.
Since the change in the law in September 2024, it is sufficient to To inform the owner in the houseThey then have two months to file an objection. But a note in the stairwell is not enough. Andreas learned from his lawyer that each owner must be personally addressed – by registered letterThis is the only way to prove later that everyone was informed and that the period began correctly. Especially important: If an apartment belongs to several people – such as a married couple – each person individually be written to.
The List of owners can be requested from the property management – they are obligated to provide this information. Alternatively, you can also look in the land register yourself. Should someone actually Contradiction insert, then this justified – for example, with safety concerns, such as inadequate fall protection during self-assembly. And the clearer and more transparently you describe your project in the letter – including the module name and installation company – the better the chances that there will be no objection.
But here too: The Sending this registered letter can be quite expensive for large residential buildings. Shipping costs of several hundred euros are not uncommon.
Another topic was the Energy law notification to the City of Vienna, Municipal Department 64. But there was also news here: Since the end of 2024, standardized small systems up to 800 watts no longer have to be registered and no longer require a permit.
Things may be different if you live in a protected zone or if your balcony power plant deviates from the norm. building permit by the Municipal Department 37 It may be necessary. A review of the relevant guidelines is always worthwhile—but outside of these special zones, a building permit is no longer required.
And finally – an often underestimated point – the InsuranceWhat if a storm blows the panel off the balcony? Or a short circuit occurs? Most household insurance companies still have difficulty with balcony power plants. Often, only electrical appliance insurance is offered, which does not include damage caused by natural forces such as hail or storms. In the course of his research, Andreas has Upper Austrian Insurance discovered: With “Klima pro” a real photovoltaic insurance – for €3.75 a month. It covers everything you could wish for: from natural hazards to operating errors. And anyone who switches their household insurance to this company right away will automatically have the balcony power plant, including up to 2 kW of storage, covered. What's more, additional battery storage can also be easily insured.
Another point that Andreas did not forget was the possible glareEspecially in direct sunlight, neighbors may be disturbed—this can also be a reason why a BKW must be removed later. In the worst case, the building inspector may even be required to dismantle it—at your own expense.
Important NOTE: The Feed-in into an energy community is currently possible with a standard balcony power plant not possible, partly because the necessary feed-in metering point is missing. However, this is set to change in the coming years.
In the course of the balcony power plant project, something big was finally created: In September and October 2024, Andras Renewable Energy Community Wienerberg initiated and founded – in short: EEG Wienerberg. This regional community supplies 100% renewable energy, strengthens local value creation, relieves strain on the electricity grids, and is also particularly cost-effective for all involved due to the elimination of some grid costs.
And the balcony power plant itself? It was finally installed by Skymax GmbH in March 2025 – and since then, it has been quietly and faithfully producing clean electricity. A story that shows: It takes a little patience, but it's worth it – for yourself, for the neighborhood, and for the climate.
As of March 2025. All information is subject to change.
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