‘Smart’ lighting as a solution to light pollution

London photo courtesy of stock.xchng

Light pollution is a real problem in our cities and towns characterized by a reduction in the visibility of the night sky, but few people realize the implications of this. Light pollution is misdirected or misused light, from sources such as public lighting and office building lights. Light pollution doesn’t just hide the beautiful night sky from us, it’s actually a side effect from a very serious issue, one that could be fixed with the right technology.

I grew up in a small town, and moved to Toronto for school when I was 20. One of the first things I noticed when I moved here was that I couldn’t see most of the night sky anymore, because it was so brightly lit from the city lights.
Many people believe that stargazers are the only people affected by light pollution, but this isn’t the case. One of the most well known issues surrounding light pollution is the death of birds as they fly into brightly lit windows at night. Other issues are raised about safety; street lights that are too bright can blind a person to the attacker hiding in the shadows, or glare from windows can reduce a drivers visibility and could cause an accident. The biggest problem however, is the root of the issue: wasted light.
BBC News recently wrote an article on this subject, as did environmental design blog Inhabitat.com. One of the most serious problem with the wasted light is that the light is produced with electricity, which means wasted resources and wasted money. Inhabitat puts it very succinctly:

To put the problem in perspective, estimates place the cost to the US in the neighborhood of $5,000,000,000-$10,000,000,000 annually. That’s $5-10 Billion dollars with a capital “B”. This is not the sum total of all outdoor lighting, this is just that portion of outdoor lighting that is so misdirected as to light up the night sky. This is an incredible sum of money to simply waste, and yet that’s exactly what we do year after year. In fact, the problem is actually increasing in magnitude and cost.

Imagine if this money were redirected to address environmental or social issues! Almost all of the environmental issues facing us could be invested in, with absolutely no reduction in any other funding because this money is being paid already. And, the night skies would be visible again.
The question is, how can this be accomplished? The answer, is to use ‘smart’ technology for our lighting as the current technology and implementation is pretty dumb. Light pollution isn’t caused by all nighttime lighting, it’s caused by misused or wasteful lighting.

One of the problems with our lighting is improper placement and direction of outdoor lighting, there is no functional reason for a light fixture to be shining light upwards if there is nothing but sky to illuminate. A perfect example of this is stadiums; many have just as many lights pointing upwards as they do on the playing field. More common though, are street lights and other public safety lights. The best way to solve this problem is with better lighting design. Inhabitat’s article specifically mentions ‘full cutoff’ street lamps, which direct a beam of light downwards to a specific area, without shining light up into the sky. The benefit of this is reduced light pollution, but also reduced operating costs and energy requirements because it’s able to light the intended area without also unintentionally lighting up surrounding areas. There are several other things that can be done to further improve on this: utilize solar powered street lights, as well as wireless controls that use timers to determine when the lights come on based on ambient light levels. In addition to this, street lights could be fitted with motion sensors to determine when there are people or vehicles nearby that would require additional light. With sensors and variable output lights, public lights would be able to maintain a safety level of light output and increase their light output only as needed.

The other main source of light pollution is from office buildings that leave their lights on all the time. Whatever the intended reason, this practice results in a tremendous amount of wasted energy and the related environmental impacts. The same technology mentioned for the street lights would also work for office buildings, which would automate the process of switching lights off and on depending on ambient light levels and building occupancy. Like a thermostat the sensors would adjust the lighting to whatever output was required to meet the set lighting level, and would reduce the lighting to the code-required safety level when the area was unoccupied. This could result in an energy savings of up to 75%.
Light pollution is costing us money, energy, and the beauty of the night sky… but by using smart technology to change our habits for nighttime lighting, we can save money, be good to the environment, and see the stars – without giving up all of the pretty city lights.

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About

Steve holds a degree in Environmental Engineering Technology from Humber College in Toronto, is a LEED Accredited Professional and a Certified Sustainable Building Advisor. He currently lives in Victoria BC and works as a green building consultant specializing in residential projects.

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