CN Tower

The CN Tower was once lit at night with incandescent lights, but they were removed in 1997 because they were expensive and inefficient to repair. In June 2007, the tower was outfitted with 1,330 super-bright LED lights inside the winch shafts, shooting up over the "bubble" and upward to the top of the tower's mast to light the tower from dusk until 2 a.m.

The official opening ceremony took place on June 28 before the Canada Day holiday weekend. The tower changes its lighting scheme on holidays and to commemorate major events. After the 95th Grey Cup in Toronto, the tower was lit up in green and white to represent the colours of the Grey Cup champion Saskatchewan Roughriders.

Programmed from a desktop computer with a wireless network interface card, the LEDs use less energy to light than the previously used incandescent lights (10% less energy than the dimly lit version and 60% less than the brightly lit version). The estimated cost to use the LEDs is $1,000 per month.

During the spring and autumn bird journey seasons, the lights will be turned off to comply with the voluntary Fatal Light Awareness Program, which "encourages buildings to dim unnecessary exterior lighting to mitigate bird mortality during spring and summer migration."