The famous lights of Piccadilly Circus came back to life today after a nine month renovation. The new lights replace the previous advertising displays with a single, interactive, 4K LED screen covering 790 m² (8,503 ft²). The dusk lighting ceremony also capped the #PiccadillyOn charity fundraiser that encouraged the public to raise money for the Barnado's children's charity by sponsoring each of the 11,848,400 pixels on the screen.

Piccadilly is one of the most famous and busiest intersections in the world. With over 100 million people passing through it each year, it isn't surprising that it's one of the premium slices of advertising real estate. It's been home to illuminated adverts since 1908 and the lights have remained on continuously except for the blackouts during the Second World War as well as the funerals of Sir Winston Churchill and Diana, the Princess of Wales.

In the latest blackout, present owner Landsec carried out the most extensive renovation of the lights ever. In December 2016, the six giant flat screens that dominated the Circus were switched off and the advertising area covered in tarps and scaffolding. The new replacement is a single wraparound LED screen measuring 17.56 m (57.61 ft) high x 44.62 m (146.39 ft) wide that is capable of generating trillions colors.

The new screen is bigger and brighter than anything installed in the Circus before and can play host to multiple adverts and news updates playing simultaneously. It also has environmental sensors that can change the screen content in response to temperature, light, weather, and other factors. In other words, if it starts raining, don't be surprised it a commercial for umbrellas starts playing. Because the sensors have raised security concerns, Landsec stresses that no images or personal information about passersby is recorded.

"The Piccadilly Lights have been one of London's icons for over a century, and are an unmissable sight for the 100 million people who pass through Piccadilly Circus every year," says Vasiliki Arvaniti, Portfolio Director at Landsec. "We know people have really missed the screen while renovation work has been carried out and both we, and the brands that light up the screen, are incredibly excited to have switched the Lights back on today. We want to say a huge thank you to everyone that has been part of the #PiccadillyOn campaign, raising money for Barnardo's."

The welcome back display will repeat itself until 11.59 pm BST on Friday October 27.

The video below shows the Piccadilly Lights coming back online.