Tower solar power plants are large-scale power plants in which mirrors that biaxially track the path of the sun – so-called heliostats – reflect direct solar radiation onto a central receiver mounted on a tower. The radiant energy is then converted into heat and transferred to air, liquid salt or water/steam. This heat drives a turbine that feeds a generator.

schlaich bergermann und partner developed the prototype for a metal-membrane heliostat of 14 m in diameter with stainless steel membranes measuring 0.4 mm in thickness. The concentrator is made of a “drum” that in turn consists of a pressure ring and tautened metal membranes on the front and back sides. The front membrane is clad with thin-glass mirrors in order to achieve the desired high degree of reflectivity. Negative pressure of just a few millibars is created within the drum by means of a fan. As a result, the membrane is deformed and the flat mirror becomes a concentrator.

Our commission was to design, plan and build telescopes for the observation of Cherenkov radiation in the H.E.S.S (High Energy Stereoscopic System).

As part of an experiment by the Fraunhofer Institute (Heidelberg) for Nuclear Physics, four telescopes were built in Khomas Highland, Namibia. The diameter of a telescope spans 12 m, creating a mirror surface of 107 m² that consists of 380 polished glass mirrors, each with a diameter of 60 cm. Each mirror can be individually motor-adjusted.

The telescope incorporates a space-frame structure design with a very high rigidity. The entire steel construction weighs roughly 60 tons. A rotating base on steel wheels and a round precision rail enable suspension and tracking, which are controlled by a servomotor.

Climatic covers want to reform commercial areas: Instead of many unrelated buildings and halls with their heterogeneous exterior, there is one large jointly used transparent cover, underneath of which different companies have their home. Thus, climatic covers show the way towards a holistic solution to eliminate the rigor of most new commercial areas on the outskirts or in the open countryside, which in many ways thwart the ambitions for a sustainable and cultivated urban development. Compared to conventional commercial areas, climatic covers are characterized by numerous advantages and new possibilities:

Heating energy demand is reduced by about one third as compared to a current commercial zone.

Conservation of resources due to the long lifetime of the cover.

Reduction of required footprint by 30 to 35% due to joint logistics and thereby compact site development and centralized space management.

Those and many more important aspects are content of the documentation “Climatic covers for commercial areas” of Jörg Schlaich, Philip Dechow and Gerhard Weinrebe.