Sketch of the differential arc lamp of 1878

The widespread use of urban street lighting began with the differential arc lamp built in 1878 by Friedrich von Hefner-Alteneck, the chief designer at Siemens & Halske. In this lamp, the burned-down carbon rods producing the light could be regulated automatically and several lamps could also run together off a single generator.

Street lighting on Potsdamer Platz in Berlin, 1882

After the successful operation of the first series-connected differential arc lamps at the Berlin Trade Fair of 1879, Siemens was awarded the contract in 1882 to install the first permanent electric street lighting in Berlin, on Potsdamer Platz and in Leipziger Strasse.

Tantalum lamp

During his search for a suitable incandescent filament lamp in 1882, Werner von Siemens, assisted by his son, Wilhelm, initially experimented with metal wires, but later changed over to carbon filaments. Wilhelm finally commissioned W. Bolton to continue this work, and he found a metal with all the desired properties, namely tantalum. The tantalum lamp was the first commercial metal filament lamp and became available on the market in 1905.

Circulux incandescent lamp

The Lumilux fluorescent lamp came onto the market during the energy crisis which began in 1973. In the course of its development, it offered the consumer 10 percent less energy consumption and more light. The Circolux with its incandescent lamp base, which was introduced in 1980, uses even less energy. It provides as much light as a 75-watt lamp but only consumes about 25 watts.

Ostar Lighting, 2005

In 2005, the Siemens subsidiary, OSRAM, put the brightest white light-emitting diode on the market. Ostar Lighting emits 200 lumens and literally puts conventional bulbs and fluorescent tubes in the shade. The average life of an Ostar Lighting unit is 50,000 hours; with eight hours of operation a day this amounts to almost 18 years.