How to "Light Right"

Just like politics, a lot of light pollution is local, and there’s plenty that you can do to improve the nighttime environment around your own home.

The first step is to fix your own lighting. Check to make sure that outdoor fixtures direct their light onto the ground, rather than spraying it upward or onto your neighbors’ property (light trespass). Simply pointing these fixtures downward reduces light pollution.

Make sure you’ve got the right amount of light for the intended purpose. If 70 watts will do, why use 400? The glare from a bright light actually diminishes your ability to see well at night, because the pupils of your eyes constrict in response to the glare — even though everything else around you is dark. Overly bright light also casts harsh shadows that could mask the presence of dangerous obstacles or even intruders.

Perhaps you have a backyard security light that’s on from dusk to dawn. But unless you’re in the habit of looking out a bedroom window all night, you’re only putting your yard on display for passers-by or even would-be thieves.

And dusk-to-dawn fixtures can be expensive to operate: as a rule of thumb, a security light that’s on all night, every night, will cost you about $1 annually for every 2 watts of power used. For example, a 200-watt fixture will run up your electric bill by about $100 per year. To get a better idea of what your outdoor fixtures cost to operate, check out this "Lighting Cost Calculator".

One easy way to improve home security, cut your electric bill significantly, and reduce light pollution is to install motion sensors on your outdoor fixtures. When the sensor triggers its light on, you’ll know that something or someone is moving around outside. A security light activated by a motion sensor will be on at most a few times per night and cost you only a few dollars per year to operate. Most models have override switches to keep them turned on (or off) continuously.