Our power grid has four different voltage levels. The higher the voltage, the lower the energy loss during distribution. From the maximum voltage of 380 kilovolts (kV) to the low voltage of 230 volts for the end consumer in private homes. Author: ZDF/3sat/nano/Marco Polo Film AG/Dietmar Klumpp/Holg
The Roman Empire defines its borders. Hadrian's Wall in Britain and the approximately 550-kilometer-long Limes in Germania are imposing security systems against unwanted immigrants and hostile attacks. Author: ZDF/Terra X/ Story House Productions/ Sigrun Laste/ Jürgen Rehberg, André Götzmann/ Oliv
About 50 billion migratory birds are on the move in spring and autumn to reach their breeding or wintering grounds. Along the East Atlantic bird migration, the food-rich Wadden Sea in the North Sea plays a crucial role. Author: 3sat/NANO/Logo (Marco Polo Film AG)/S. van Iersel, T. Visser, A. Scheur
