Monday, December 10, 2007

University district lighting project can protect environmental values

University district lighting project can protect environmental values

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The cities of Champaign and Urbana and the University of Illinois have recently embarked on a cooperative project to update the outdoor lighting in the university district over the next 10 years.

Done well, such a large-scale project affords some excellent opportunities for protecting environmental values. Better still, taking advantage of these opportunities need not increase the overall cost of providing lighting, or detract from safety and security. That’s because the qualities that make outdoor lighting good for people also make it good for the environment.

I think most of us are so accustomed to the effects of poorly designed outdoor lighting, which are sometimes referred to collectively as “light pollution,” that we hardly even recognize them. But recognizing what’s wrong with much of our current outdoor lighting is important as we look toward the future. And don’t take my word for it. The next time you’re out at night, I bet you can spot all of these problems.

First, look for fixtures that direct bright light at or near a horizontal angle. Examples of such fixtures include the boxy-looking wall packs that are sometimes affixed to buildings and the old-style, drop lens cobra head fixtures that loom over many arterial streets. (Newer, flat lens cobra head fixtures direct light toward the ground.) Notice that as you walk or drive toward such fixtures it actually becomes more difficult to see obstacles and other dangers in front of you or off to your side. Notice also how bright light that shines horizontally creates harsh shadows and that it intrudes on neighboring properties.

Next, pay attention to fixtures that direct some part of their light up into space, like the historic-style globes around town, and the super-bright, so-called “security” lights on power company poles. The most direct bad effect of such fixtures is sky glow, the light that denies modern urban dwellers one of the most basic human experiences, the opportunity to look up at the stars and wonder.

Beyond producing undesirable visual effects, bad lighting also wastes a lot of energy. One study conducted in the mid 1990s calculated the cost of wasted outdoor light in the U.S. to be about a billion dollars a year, and there’s no reason to suppose that figure has gone down. The energy used to produce that wasted light would equal at least six million tons of coal or 23 million barrels of oil.

So what would a good campus lighting project look like?

Gary Cziko, a University of Illinois professor and Urbana resident has proposed what seem to me five very useful criteria for evaluating the options, all beginning with ‘E’:

• Efficient—fixtures should produce the greatest amount of useful light per watt of electricity used.
• Effective—fixtures should direct light downward (as depicted in photo, by Gary Cziko), and the light they produce should be of a color that enhances vision.
• Economical—the costs of operating and maintaining fixtures should considered in conjunction with the costs of purchasing and installing them.
• Ecological—lighting should be limited to areas where it is truly useful so that plants and wildlife are not disturbed unnecessarily, and attention should be given to disposal issues since some lights contain mercury.
• Esthetic—fixtures should be pleasing to look at both during the day when they are off and at night when they are on.

With the right design, the University District uniform lighting project can create an attractive space for people without creating undue stress on the environment.

You can see Gary Cziko's presentation on U of I campus lighting at:

Much more information about the why and how of good lighting can be found at the website of the International Dark Sky Association: