All of the electrical power comes from the sun and the heat comes from the earth, according to a statement from Hoval, which is headquartered in Vaduz and was a partner in the project with its heat and hot water production solutions. All the components such as the building envelope, building technology and energy concept push the boundaries of what is technically possible, explains the Umweltarena. The building also features the most energy-efficient household appliances on the market. In total, energy consumption can be halved from 4,400 kilowatt hours per apartment per year to 2,200 kilowatt hours without sacrificing the comfort of the residents.
According to Hoval, non-reflective photovoltaic modules are used as facade elements, and the roof is covered with modern, high-performance photovoltaic modules. The solar energy is converted into an electric current and stored in batteries for one to three days for daily use. For long-term storage, the building features a new conversion process from electric current to hydrogen: the hydrogen is temporarily stored and can be converted back into electric and thermal energy when required. Part of the solar energy is also used to run the heat pump to produce hot water, operate the underfloor heating system and charge the short- and long-term hot water storage.
As a heat source, a water/water heat pump with a geothermal probe is used: the Hoval 19, which Hoval describes as a “standard product”, is used in thousands of other multi-family homes and industrial buildings.