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Light pollution and LED technology

NYC at night

Most people are aware of air, water and land pollution. But what about light pollution? The misapplication or excessive use of uncontrolled artificial light can have serious consequences for our environment. Types of light pollution include:

  • Visual clutter: light sources grouped together in a way that is bright, confusing and excessive
  • Glare: extreme brightness that leads to visual discomfort or disability
  • Light trespass: light where it is unwanted or not needed
  • Skyglow: brightening of the night sky over inhabited areas, such as cities and towns

Ken Siderius, an expert in outdoor architectural products and controls with Eaton’s Lighting Division, talks about light pollution and how modern LED technology can help keep our paths illuminated and our night skies dark.

Why is it important to reduce light pollution?

Light pollution has a significant impact on our environment. For example, it can alter the migration paths of turtles and birds as well as animals’ nesting and mating patterns. Light trespass can cause birds to crash into towers, because it interferes with navigation.

Sky glow is a problem. It scatters lighting directed above the horizon off water vapor and clouds and obliterates stars in the night sky.

There are also physiological effects on humans. Sky glow and light trespass can alter our circadian rhythm, in turn interrupting our sleep patterns.

These days, light trespass is a big deal. It’s becoming more important to observe property lines in regard to illumination, and legislation has even been introduced to enforce this. Compared to HIDs, LEDs make it much easier to avoid light trespass and respect property lines.

How do LEDs reduce light pollution compared to alternative sources?

LEDs are an inherently controllable source, whereas in the past, other sources were larger and more difficult to control. In optical design, the smaller the source, the easier it is to control, and LEDs are extremely small. We can actually control 100 percent of the output of an LED luminaire. On the other hand, with older sources, up to 70 percent of the light coming out of the fixture might be uncontrolled. That’s a lot of wasted light, and it ends up in the wrong places.

What are examples of areas leading the charge to reduce light pollution?

In general, the International Dark-Sky Association has been our pacesetter. Legislation like California’s Title 24 has been created in an effort to reduce the state’s energy consumption and control light pollution. Third-party certification programs from organizations such as the DesignLights Consortium, ASHRAE and Illuminating Engineering Society (IES) also set standards recognized and followed by most of the industry.

How will LED technology affect outdoor lighting in the next few years?

LED technology is growing by leaps and bounds, and what we achieve as a whole will invariably affect outdoor lighting. We’re also getting better at integrating lighting controls to manage consumption of light and energy.

We’re still at the beginning of a massive retrofit movement, where street lighting and large commercial projects are the low-hanging fruit. Eventually, the industry will begin to adopt more architectural lighting solutions. We’ve been concerned with driving lanes and parking spaces, but moving forward, we’ll focus more on the pedestrian experience.

The pedestrian space is key to many urban renewal projects. Municipalities have realized that in order to encourage commercial activity in business districts, they have to focus on the pedestrian experience. They’re looking for architectural lighting solutions at the pedestrian level including public spaces like pathways in entertainment districts. In general, cities couldn’t afford to focus on these things in the past, but LED technology makes them much more affordable today. LEDs use significantly less energy than sources like HIDs, and they last so long that the maintenance is a lot cheaper, too. Now, cities can light some of those dark, more hazardous spaces that have always been poorly lit, improving security. Local leaders are realizing LEDs can help them create a visual environment that brings more people out to experience all their city has to offer.

It’s also important to remember that though today’s technology is advanced, it still has room to grow. For example, our industry is putting a lot of energy into reducing the amount of blue light in LEDs and moving toward color temperatures in the 3,000-4,000K range (from 6,000K). We can already offer a broad variety of color temperatures that weren’t possible in older sources, so we’re making great progress.

Why are LEDs growing so quickly in outdoor lighting?

New construction is down, which means renovation of existing spaces is up, and lighting is a great way to improve what you have. In fact, currently 75 percent of our business is on the retrofit side. Older cities, in particular, are seeing the value. For example, New York is spending a lot of money to make its downtown more inviting, and that will only continue. The Big Apple is just one of many maturing cities across the nation that are now focused on bringing people back into downtown spaces by upgrading the infrastructure, and lighting will always have a seat at that table. 

The Lighting reSource