Between 1880 and 1913 Berlin was the electrical capital of the world - Elekropolis. Innovation in electrical engineering - especially the invention of the dynamo and the electromagnet - powered Berlin into twentieth century. All this symbolised in the 1920s by the Osramturm, the glowing light-bulb manufacturer's light-tower that projected the mantra: "Licht ist Leben": light is freedom. Darkness fell, however, on the industry during World War Two. The two pioneer firms, Siemens & Halske and AEG, were reduced to rubble or penury or both and Berliners went back to oil-lamps..

Today, thirteen years after the Wall was torn down, Berlin is rebuilding its cultural and political landmarks with gusto, with lights and with an acute sense of its own history. The epicentre of Berlin's electrical rejuvenation is the Potsdamer Platz. A hundred years ago, electric trams passed daunting neo-classical architecture. The Kaiser, the cavalry, returning prisoners of war, flower-vendors, absolutely everyone passed through Potsdamer Platz. It was the Times Square of Berlin until the Wall was build over it. Then West Berliners had to stand on raised steps to peer through barbed wire at the checkpoints, tank traps, and observation towers that their cultural heartland had become.

Potsdamer Platz is now returning to its former glory through the architect Helmut Jahn's development of the Sony Centre:. This is an open concourse with tented roof, a cultural and commercial forum and home to Berlin's film archive and museum, Imax cinema, Deutche Bahn bank, several restaurants and bars, the Arkadia shopping mall, and offices including Sony's European headquarters. As darkness falls the whole emporium become an evening light-show that has echoes throughout the new Berlin - from the (Norman Foster) dome of the Reichstag to the Galeries Lafayette department store on Friedrichstrasse to the popular shopping street, Kurfürstendamm. In all this Berlin seeks, once again, to reclaim the soubriquet, electric city.