Photovoltaic power for household appliances, an electric car and heating

13.08.2020 / Poland

Zero-energy house and integration of the electricity, mobility and heating sectors

Katarzyna Baran lives in a zero-energy house in Poland and uses a roof-mounted PV system of just under 10 kWp to generate power. A Fronius Symo 10.0-3-M inverter produces approximately 10,000 kWh of CO₂-free solar energy a year. Ms Baran uses this not only for her household electrical appliances but also for the electric heating and to charge her electric car.

Heating and charging an electric car with PV energy

In addition to the normal loads, Ms Baran’s zero-energy house also supplies the heating and her electric car with PV power, meaning all her energy needs are covered by solar energy. This shows photovoltaic systems pay off from the first day of their investment, as the energy for heating and charging electric cars would have to be purchased without a PV system. However, since Ms Baran can use the energy generated from her own roof, the investment costs have paid for themselves within a few years.

“I built my first house eleven years ago. At the time, I decided against a PV system – the prices were simply too high. When I was building my new house, the situation had changed. Now that prices are significantly lower, my system will pay off in fewer than eight years, even without a public subsidy.”

PV system pays off within a few years

Thanks to the integration of the electricity, heating and mobility sectors, Ms Baran is rewarded with good self-consumption rates.

Ms Baran's system pays off in fewer than eight years.

System monitoring with Fronius Solar.web

Ms Baran’s system is registered in Fronius Solar.web. Both her and her installer can conveniently monitor the system and analyse the values via the app. When a service is required, the installer receives automated messages via e-mail, which enables them to quickly fix defects. They can also carry out updates for the system via remote maintenance, saving on costs for travelling to the physical location of the system and staff deployment.

Analysing PV production and consumption

As an installer, you can also give your customers good advice on electricity consumption behaviour – the analysis of the production and consumption of the PV electricity clearly shows how the residents can better use their loads to optimise their self-consumption.

One potential improvement for Ms Baran’s PV system would be the installation of additional smart meters for strategically important loads such as the heating or the wallbox. With this measure in place, her installer could analyse the system in greater detail via Solar.web.

Upgrading the PV system to include a storage system

With the help of Fronius Solar.web, it is possible to simulate the effect of upgrading a system with a battery in terms of savings and self-consumption. This tool can be used by installers to demonstrate possible system upgrades to their customers. By configuring a few settings, they can simulate the impact of integrating a battery into any system registered in Solar.web that has a Fronius Smart Meter.

Reducing your carbon 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 annually. This corresponds to a CO₂ saving of around 5,000 kg.

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System data
Size of installation	9.9 kWp
Fronius products	Fronius Symo 10.0-3-M Fronius Smart Meter
Modules	Selfa 275W Full Black
Annual yield	9,800 kWh

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.