Germany is testing the grounds for sustainable urban construction with its surplus energy house in Berlin. The centre of the German capital has become an experimental point for the most advanced technologies in low-carbon building and renewable energy. The Plus Energy House with Electric Mobility, or Effizienzhaus Plus , constructed by the Federal Ministry of Transport, Building and Urban Development, does not only meet the energy needs of its occupiers but also stores extra energy that can either be fed back into the grid or be used for charging an electric car.
One year after its opening in Berlin, the house became a home. A four-member family has been living there since March 2012 in order to put the 130 sq. m experimental house into use in real-life conditions. The data produced in the span of two years will serve as a basis to calculate whether such a building is economically viable, as energy efficient as expected and whether it is easy to maintain and provide its occupiers with living comfort. After the testing period, the house can be dismantled and recycled.
First and foremost, the architectural design of the building has minimised the heat loss of the walls through insulation, which reduces the loss of energy. Thus, demand for energy for heating and lighting remains low. In relation to consumption, abundance of energy is produced through an air-source heat pump and photovoltaics on the roof and facades of the house. On sunny days, solar energy can be accumulated in a battery and used during the night. The ability of the house to fulfill both the home and electric vehicles’ needs has earned its motto: “My house – my filling station!” When the energy consumption in the house is lower than the production, the surplus can be exported to the grid. During the winter, electricity can be imported back from the grid. This ensures that the house produces an energy surplus over the course of one year.
Smart living: engaging residents’ awareness
The intelligent processes in the house are integrated in a smart system that adjusts according to the weather conditions forecast and the behavioural patterns of the residents. A key aspect of the house is also the involvement of its occupiers in controlling the devices through smart technology, e.g. touch-screen panels and smartphones. One of the challenges of the test is to determine whether such houses are user-friendly. This is one of the areas that has been identified as disadvantageous in homes with very advanced technology. Users are sometimes unable to adapt to the new living conditions. It is also important to observe the relation between smart technology and residents’ decisions. Being able to constantly and easily track the energy production and consumption in the house, occupiers can make better educated choices on whether to switch the lights off when they are not in the room, whether to turn the heating down when leaving the house, or to leave the computer on stand-by when it is not in use. These choices of everyday living become a lot more tangible in the Plus Energy House through the smart technology; therefore, the residents’ awareness is engaged more strongly in making decisions on their energy consumption.
Data on the energy usage of the house is also available on viewing screens accessible to the open public as well as on the website of the Federal Ministry of Transport, Building and Urban Development (in German). For tech-addicts, a detailed description of the technical specifications of the house, including information on the frame, construction, superstructure and the materials used is available online.