Heizwerk Köln-Südstadt

With an output of around 1.2 megawatts, the plant was, at its launch, the first major power station in Germany built on alternating current. On 12 September 1891 the first electricity flowed to Cologne's Volksgarten, lighting the 21st German Jurists' Convention there. The plant formally began operations on 1 October 1891, initially supplying the Old Town and the Ring boulevards: parts of the public street lighting, small motors in trades and factories, and lamps in a number of households.

The first structure, built in 1883/84, was the pump house of the Severin I waterworks, followed in 1890/91 by the first electricity works. These early buildings, with their yellow brick façades, draw on German Renaissance and Classicist styles. The later red-brick buildings echo older traditions still further back: the second electricity works in Romanesque forms, the plant housing the alternating-current generators in neo-Gothic style — the latter partially reconstructed in the 1970s. The site was built and operated by the "Gas-, Elektrizitäts- und Wasserwerke Köln AG (GEW)".

Since a 1963/64 modernisation, the plant has also supplied district heating; in October 1966 broadcaster WDR became one of its first major customers. In 1994 it was converted into a combined-cycle gas and steam turbine plant, comprising a gas turbine unit, a waste-heat boiler with supplementary firing, and a steam turbine unit. Until the end of 2016 it generated around 100,000 MWh of electricity per year through natural-gas-fired combined heat and power. Electricity generation ended once the new "Niehl 3" unit at the Cologne-Niehl combined heat and power plant, built in 1977, came online.