The City of Heidelberg invited architects to build additional thermal energy storage and, at the same time, create space to educate the public and involve everyone with energy sustainability and climate protection. A steel structure, external to the energy storage core, provides an observation deck, educational displays regarding energy conservation, and a rooftop restaurant, to create an appealing destination. This structure is built with horizontal radial main beams above the heat storage and diagonal-truss column support for elevation on the shell.
Although elevator access is available from the entrance area, visitors can also choose to heighten the sense of adventure by walking up the dual-purpose pedestrian path wrapped around the truss columns. This external, enclosed path provides a unique learning experience, but also provides a functional escape. Climbing 50 meters to the top, the surrounding landscapes and neighborhoods and the impressive size of the storage can be experienced from different perspectives.
After dark, the visitor is accompanied along the path leading to the roof by a steady rhythm of restrained light lines with individually controlled LED colored light technology. Motion sensors cause the lights to change color as pedestrians pass, creating a kinetic light sculpture visible from the surrounding area. The lighting could be programmed in a number of different patterns, i.e., to dynamically map the temperature inside the storage core.