In 2016 Kenneth Saxskiold from NorthLED in Roskilde, Denmark, came by and asked if we could assist in developing new LED lamps for football stadiums that could reduce light pollution. We raised 3 Mio DKK from EUDP and developed a new 3100W LED lamp that reduced light pollution by 90%.
Traditional stadium lights today are based on metal halide lamps. Typically 18 lamps (2000 Watts each) for a 250 Lux football field. Although they are quite effective in terms on light output per consumed electrical Watt they suffer from having rather large light emission points, which makes light shaping really difficult. Hence, a large fraction of the light escapes to the surroundings.
LEDs have relatively small light emission points, so we developed a lighting solution based on only six light panels, each panel comprising 350 LEDs with a specially designed free-form acrylic lens in front of each LED. In this way, we could quite accurately shape the light from each LED to match the football field.