Continued: Paul Bogard: Wasted watts

In Monday's Star Tribune, Eden Prairie's public-works director explained that the city uses $750,000 a year on streetlights and that "savings of even 10 to 15 percent" would be significant ("Suburbs looking to save on lighting"). Considering competitive bids for new streetlights and exploring the use of LED lights, as the article reports Eden Prairie and other communities in the Suburban Rate Authority are doing, certainly are options for cutting costs. But the most effective means might be the easiest: choosing streetlights that are more efficient and effective.

We use far more artificial light than we need, and we pay for all that extra energy. Once you begin to notice this overuse, you see it everywhere. Shopping-center parking lots, gas stations and car dealerships are easy examples. Most streetlights spray their light in all directions, burning through the night whether or not a single car, cyclist or pedestrian passes under their glow. In addition, we often illuminate spaces and places that we don't need to, such as the night sky.

Anyone who has ever marveled at a dark, starry night knows that the night sky above our cities and suburbs is a pale version of what it used to be. The reason? Our overuse of artificial lights. In fact, fully half the light in the night sky has been sent directly skyward, much of it excess from poorly designed and overused streetlights. Simply by changing this situation, communities like Eden Prairie could save significant money regardless of which company they use or whether they switch to LEDs.

Manufacturers now offer streetlights that are designed to reduce or eliminate the light sent into the sky. In doing so, they actually increase safety by eliminating the glare caused by older lights, glare that is a particular problem for the increasing number of elderly drivers on our roads. The old equation that more light equals more safety is rapidly being replaced by the understanding that more safety comes rather from light directed to its task, and that after a certain point, more light only means reduced safety, lost night skies and wasted money.

Additionally, scientists are increasingly understanding the way that artificial light, through its disruption of our body's production of melatonin, has serious health consequences, with connections to sleep disorders and higher rates of breast cancer. In short, human beings evolved amid sunny days and dark nights and need both for optimal health.

Nocturnal and crepuscular (active at dawn and dusk) species of wildlife suffer their own health consequences of excess artificial light, as the darkness in which they have evolved disappears. One example: More than 400 species of songbirds migrate at night in North America and are often disoriented by lights, slamming into bright buildings or circling artificial lights until they die from exhaustion.

And while it's hard to put a price tag on the health of our souls, there's no doubt that something of the human experience is lost when our lives no longer include the pleasure of spending a summer night staring into the cosmos or the joy of just seeing the Milky Way soaring overhead.

The good news is that in a world full of problems that can seem beyond our control, this is one we can indeed do something about -- as individuals, as communities, as a society. Everything from simply turning off our house lights at night to buying shields for our porch lights and yard lights to urging our communities to choose streetlights that don't send light into the sky can make a difference.

The Suburban Rate Authority has -- as all Minnesota communities do when it comes time to replace old streetlights -- a wonderful opportunity. Understanding that we now use far more light than we need and that the costs go beyond money, communities should seek to replace their old streetlights with fixtures that are designed to reduce glare and light pollution and to increase safety and energy savings. The benefit will be shared by all.

Paul Bogard is an assistant professor at Northland College in Ashland, Wis., and the editor of "Let There Be Night: Testimony on Behalf of the Dark."