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Home owners

Photovoltaics in a zero-energy house

A PV system pays off within a few years

Living in a zero energy house? What does this mean? Katarzyna Baran is an interior designer and enjoys the benefits that come with living in this type of house. It uses an inexhaustible source of energy – the power of the sun.


The photovoltaic system on the roof enables Ms Baran to produce her own energy for all aspects of daily life such as electricity, mobility and heating.

What is a zero energy house?

The term “zero energy house” is used when the amount of externally sourced energy can be offset by the self-generated energy (e.g. by a photovoltaic system) during a certain period of time.

A PV system pays off within a few years

Katarzyna Baran had a PV system of just under 10 kWp installed on the roof of her house and says “Eleven years ago, I built my first house. At the time, I decided against a PV system as prices were considerably higher than they are today. It’s completely different now. Prices have fallen dramatically and even without a public subsidy, a PV system will pay off in fewer than eight years.”


Many countries also offer financial support for the installation of a PV system. If this is taken into account when considering the investment costs for installing a PV system, it pays for itself even quicker.


Katarzyna Baran has found another way to achieve a faster ROI on her PV system.



Photovoltaics and e-mobility – a perfect combination!

Ms Baran drives an electric car, which she charges with the PV energy she generates herself. In doing so, she is also increasing her rate of self-consumption. And the higher the degree of self-consumption of a PV system, the faster it pays for itself. Moreover, Ms Baran is no longer dependent on rising fuel prices. No matter how the price of diesel or petrol fluctuates, Katarzyna Baran charges her car with the electricity she produces herself, meaning she drives at cost price.


Solar energy for heating

In addition to powering her car, Ms Baran can also use green PV energy for her heating, which is electric. The energy for this also comes from the photovoltaic system. Without a storage system it is not possible to make it through the whole winter without purchasing electricity, but Ms Baran can generate part of the required heating power herself. This also has a positive effect on the self-consumption rate. And it also means that the PV system rapidly pays for itself.



» My electrical appliances run on green energy. «



Online monitoring of the PV system

Katarzyna Baran uses the Fronius Solar.web app to keep an eye on the PV system’s yields. Thanks to this practical app for smartphones or laptops, she can see the yield that her system is generating and where the electricity is being used 24/7. Ms Baran is extremely satisfied with the system: “This monitoring makes it possible to optimise the house so that we use the majority of our PV energy ourselves. Our electrical appliances run when we have enough electricity of our own which means we hardly have to buy any electricity from the grid.”

Reduce your own CO2 footprint

In addition to the obvious financial benefits, Ms Baran is also reducing her carbon footprint. Her system generates approximately 9,800 kWh of clean, sustainable photovoltaic energy every year. This corresponds to a CO2 saving of around 5,000 kg.


“Protecting the environment is very important to me,” stresses Katarzyna Baran.

About the system:

System size: 9.9 kWp
Fronius devices:

Fronius Symo 10.0-3-M

Fronius Smart Meter

PV modules: Selfa 275W Full Black
Annual yield: 9,800 kWh
ROI: Approx. 8 years
CO2 saved/year Approx. 5 tonnes, which is the equivalent of around 24,500 kilometres driven in a car.