This was a different kind of project involving the transformation of an old farmhouse in the foothills of the Alps: the aim was to create a sustainable and (as far as possible) self-sufficient surplus-energy building. The Langes Haus development should also be able to operate entirely on local renewables.
It was important that people attending the academy in the building feel comfortable in its seminar rooms, kitchen and bedrooms. Heating and visual comfort had to meet the highest standards. To answer the brief, Transsolar used unneeded wood in a 100-hectare forest next to the farm. The source of the renewable energy: wood chips.
The energy system developed for the building runs in parallel to the energy grid, resulting in a net energy surplus. Overall, this makes the Langes Haus project a 'surplus primary energy building'. If there's a cut in public electricity supplies, the building owners do not need to worry about the lights going out or occupants feeling cold. The building has its own unit for managing electrical loads and the electricity supply, and the system automatically jumps into action to control a wood-fired power system, photovoltaic units, electrical energy storage and any areas of restricted consumption. Effectively, this turns the old farm building into an 'energy island'.