A detached house in Dresden's Weixdorf district has relied on a sustainable heat supply from a brine-to-water heat pump ever since it was built. With a heat output of 10 kW and a generously dimensioned ground collector (600 m of pipework in 300 m of trench), the building is heated efficiently and reliably.
Energy optimisation was further enhanced by the installation of a large-scale photovoltaic system with around 20 kWp (east, west and south-facing). since 2018, the system has been supplemented by the integration of an E3/DC home power plant. This allows the solar power generated to be used intelligently for the heat pump, household electricity and an electric vehicle.
The result is almost energy self-sufficient operation: the remaining electricity costs for the household, heating and hot water, including electromobility, are around €1,000 per year. However, these costs are offset by the additional feed-in tariff, meaning that practically no ongoing energy costs are incurred.
This project impressively demonstrates how the combination of geothermal energy, photovoltaics and energy storage can be used to realise a highly efficient and virtually cost-neutral energy system even in existing buildings.