The project involves a mid-terrace house built in 2016 in the Cotta district with a living space of 148 m². The building is fuelled by gas heating (heating output 10 kW), which is supplemented by a solar thermal system for heating water.
To ensure a sustainable energy supply, the existing system technology was expanded to include a photovoltaic system with 9 kWp, which has been in operation since 2023. Both the south and north roof surfaces are fully covered with PV modules. According to consultation with the consumer advice centre, it also makes economic sense to use the north side. An electricity storage unit with a capacity of 10 kWh was also installed in 2024.
The system combines gas heating, solar thermal and photovoltaic technologies to create a hybrid energy mix. The aim is to maximise self-sufficiency and increase efficiency in building operation.
The investment costs for the photovoltaic system amount to around €16,000, with an expected amortisation period of around 11 years. The battery storage system costs around €3,500 and is expected to amortise after around 13 years. After the amortisation period, long-term, largely low-maintenance electricity generation with an economic surplus can be assumed.