Home » Learn About Solar Lighting » Dark-sky controls ensure no light is wasted

Data shows that 80% of people can’t see the Milky Way, mostly due to increasing light pollution as our cities grow.

Updated on November 23, 2017

Increased light pollution worldwide is a topic of conversation lately—and LED lighting is taking the brunt of the blame. The journal Science Advances published a study indicating that from 2012 to 2016, our planet’s artificially lit outdoor area has grown by 2.2% per year. An NPR article discussing the study explains that the widespread use of LEDs, which are replacing high-pressure sodium bulbs and other energy-wasting lights, are cheaper, and therefore we are using more of them.

But the NPR article, and another from the BBC, also quote one of the researchers about the importance of lighting design and directing light where it’s needed. And where it’s needed is not in the night sky, a message the International Dark-Sky Association (IDA) has been advocating for decades.

What is the IDA?

The IDA works to reduce light pollution today and for future generations. Reducing light pollution not only helps us see the night sky better, but it also helps reduce the effects of electric lighting on the environment and cuts down on energy use.

WATCH: Learn the basics of the dark-sky movement

DID YOU KNOW? In addition to the IDA, the Consortium for Dark Sky Studies is also a major proponent for keeping the night sky dark. In fact, the organization has developed an interdisciplinary undergraduate minor in dark sky studies.

What does the IDA recommend?

Sol’s dark-sky controls help ensure our lights meet the IDA’s recommendations.

The IDA advocates for any required lighting to be used wisely to minimize light pollution; therefore, lighting should:

Only be on when needed:

• Our operating profiles allow you to select on-times that align with your application. For most applications, the standard, dark-sky friendly operating profile is 5 hours on from dusk, then dim until 2 hours before dawn. For street and roadway lighting, the standard is 7 hours on from dusk, then dim until 2 hours before dawn.

Be no brighter than necessary:

• We provide information on the lowest recommended light levels to help save money on system costs. Our standard scheduled dimming profile is 100% for 5 hours, then dim to 30% overnight, followed by 100% for 2 hours before dawn (for street and roadway lighting, the standard is 7 hours at 100%, dim to 30% overnight, followed by 100% for 2 hours before dawn).

Only light the area that needs it:

• Our calculations for lighting layout ensure optimal light coverage so that light is only placed where intended, helping improve visibility and overall light quality.

Minimize blue light emissions:

• Our recommended LED fixtures have a 3000K light output for a warm, comfortable color temperature. Unlike in the past, these LED fixtures can reach this warmer output without using more power.

Be fully shielded (pointing down):

• Our fixtures offer a built-in shield for a dark-sky friendly BUG rating (backlight, uplight, and glare measurements from a fixture).

What does BUG mean?

BUG refers to the types of light that escape from a luminaire, and stands for:

• Backlight (green section below): Directed behind the mounting pole—in the opposite direction it’s intended.
• Uplight (gray section below): Directed above the luminaire and causes artificial skyglow. This is what affects astronomers and anyone looking up to watch the stars.
• Glare: Emitted at angles known to cause glare—which at best is annoying and at worst, visually disabling. This unnecessary light could shine at the front or rear of the luminaire.

 

 

How we reduce light pollution

At Sol, we use Dark-Sky Compliant LED fixtures and scheduled dimming to help minimize light pollution—helping provide light where and when it’s intended. For example, our dark-sky friendly lights in Beaumont, California, add light only on the sidewalk, and not on the house behind it, or in the night sky above:

 

 

Get started with dark-sky friendly lighting

>> See more examples: Check out the Dark-Sky Compliant LED fixtures in an installation in Chris Hotts Park, San Jose, California.

>> Explore other benefits of solar-powered lights: Discover how solar lighting will benefit your community, help it become future-proof, and more.