The Cost of Wasted Light

Approximately 35% of outdoor lighting is wasted light—light that shines upward or sideways instead of where it’s actually needed. This contributes to skyglow, but it also represents a major energy loss.

In the United States alone, it’s estimated that $3 billion is wasted every year on inefficient outdoor lighting. 

Here are some examples of wasted light:

• Lights that aren’t shielded send energy into the sky instead of the ground
• Over-lighting uses more electricity than necessary
• Lights left on all night often serve no purpose

All of that wasted energy doesn’t just cost money—it also means increased fossil fuel use and higher carbon emissions—about 15 million tons of carbon dioxide is emitted to power outdoor lighting each year in the U.S. alone.

The good news? This is one of the easiest environmental problems to fix, by:

• Using fully shielded fixtures
• Choosing the right brightness—more isn’t always better
• Turning lights off when they’re not needed

Better lighting isn’t about using more light—it’s about using light smarter.

Protecting the night sky can save energy, reduce costs, and benefit the environment—all at the same time.

Read more: Shining Some Light on the Vanishing Night

Read more: How Artificial Light Affects Us

Read more: Wildlife & the Night