1 of 2
This motion-sensing, two-bulb floodlight, mounted over a garage door, stays on for only 60 seconds after no motion is detected.
Photo by James Dulley
2 of 2
A tall, die-cast metal landscaping light brightens a large area to double as a security light. The large-diameter top limits light pollution of the night sky.
Photo courtesy of Hadco
Question: I’d like to add outdoor lighting at my home for security and entertaining. How can I brighten outdoor spaces without driving up my electric bills?
Answer: Outdoor lighting can be effective for security, but it can also up utility bills if done improperly.
Security lighting is usually on all night; entertainment lighting is not. So choosing the proper security lighting will have a greater impact on your utility bills. Installing just two 150-watt security lights and keeping them on all night can increase your electric bill by more than $100 per year.
As you plan your lighting, remember that security lights are not always best for entertaining and vice versa. Make your security and entertaining lighting plans independently, then check to see where they overlap.
Do an outdoor walk-around inspection of your house at night to see where additional lighting might help. Sometimes the brightness from a neighbor’s home will illuminate dark, suspect areas.
When planning outdoor lighting, make an effort to minimize nighttime light pollution. Bright lights can create problems for wildlife and annoy neighbors. I can barely see the stars on a clear night due to the excessive lighting in my subdivision. If you install floodlighting, mount a directional light shield over it.
Brighter lights don’t necessarily provide more security. Lower lighting levels are more effective because the human eye doesn’t adjust quickly from a very bright area to a darker area. If lighting is less bright, it’s easier to see movement in darker areas where someone might be hiding.
Keep in mind, the wattage of a lightbulb does not determine how much light it produces. Wattage refers to how much electricity a bulb uses. Instead, look for light output—measured in lumens—on bulb packaging.
Compact fluorescent lamps (CFLs) and light-emitting diodes (LEDs) produce more lumens per watt of electricity compared to standard incandescent bulbs. For example, an L22 array LED fixture uses less than 25 watts to produce the same light output (about 1,800 lumens) as a 100-watt incandescent bulb.
Motion-sensor lights are both efficient and effective for security. When the light comes on, a would-be thief assumes he has been seen. They also catch neighbors’ attention. Consider one with two-level lighting. You can switch it on for low-level background lighting; it only switches to full brightness when motion is detected.
Wherever there is access to full sun, consider solar-powered, motion-sensing floodlights. These lights continue to operate even after a few consecutive cloudy days with little recharging sunlight.
With low-cost, standard, 120-volt outdoor lighting fixtures, try using CFLs. These use only one-quarter as much electricity as standard incandescent bulbs and last at least 10 times longer. The overall savings will pay back their higher cost many times over. CFLs do not always work well in cold outdoor temperatures and take a little while to reach full brightness. Try one or two first, and read the packaging to see if the bulb is intended for outdoor use.
LEDs, another super-efficient lighting option, are not affected by the cold. With a bright white light output, LEDs last up to 50,000 hours. Their light output is directional, so they are best for lighting specific targeted areas.
To light a larger area for an entire night, LPS (low-pressure sodium) fixtures are efficient. The fixtures are fairly expensive, and they start up very slowly to reach full brightness. The light quality is monochromatic (yellowish), so they would only be applicable for security and not for entertainment lighting.
Email questions to Energy Q&A, mail them to South Carolina Living, 808 Knox Abbott Drive, Cayce, SC 29033, or fax (803) 739-3041
_____
Get More
These companies offer efficient outdoor lighting:
Energy Focus - (888) 704-2276
Hadco - (800) 331-4185
Idaho Wood - (800) 635-1100
Kim Lighting - (626) 968-5666
Wave Lighting - (877) 870-9283