In Germany the first house producing twice the energy it consumes

At number 87 of Fasanenstrasse in central Berlin was born what could be the new frontier of sustainable, energy saving and householding at the same time. Energie Plus-Haus, a three million euro project, funded by the German Government, is the pride of the Minister of Transport Peter Ramsauer.
The first house in the world producing twice its energy needs has a floor area of 130 square meters and is designed for a typical family: two spouses and two children. The outer walls are completely covered with solar panels, a geothermal pump provides thermal energy, and all the materials used in construction are energy efficient and completely recyclable.
A home with zero impact, which produces energy for the needs of a family (including the electric cars that came with the building) and enters a quantity in the network. It seemed a utopia but it is now reality.
The perfect home is  going to be habited by a test-family. Now, it remains to be calculated - it will certainly be a decisive factor for the development of this project - how much it will cost to mass-produce, sell or rent these new houses, but the elimination of energy costs, combined with a constant gain for the sale of energy produced by the house itself, could balance a higher initial price.