The world's most modem trade fair centre has yet another superlative feature to offer: On its roofs it has the world's largest and most modern photovoltaic (PV) plant with an installed output of 1 Megawatt. This plant feeds electricity into the centre's internal medium-voltage network and features technical innovations which set new standards in the area of large PV plants. It also shows architects and civil engineers a fine example of how a 21(st)-century multifunctional building might look.