The ‘Stuttgart 22‘ vision by LAVA architecture and Transsoalar Klimaengineering seems to be a “lower cost” approach to the planned controversial conversion of the heritage main train station in Stuttgart, Germany (‘Stuttgart 21‘ (Wikipedia) , The New Heart of Europe (official site)). This alternative study is focusing on a visible renewable energy approach in order to achieve CO2 neutrality and a compact work/live downtown environment. A 200m solar updraft tower is utilizing the stack effect of warm air rising from within a double-skin, transparent roof up through the tower in order to power a turbine. The roof as well serves as a photovoltaic plant. These combined effects are thought to be sufficient to serve the 3000 new residential units within the new development. The tower could be the visible icon of a new era. This concept was presented by Prof. Tobias Wallisser from LAVA architecture at the Creativity Worldforum in 2009 and is available to watch at (follow the link and fast-forward to about 2/3 of the recording) ..

Via greenbuilding magazine (As the article is in German please use Google Translate to get an idea of the content ;-)) ..