Fall Home Improvement Tab

Someone forgot to turn out the lights…

…and that means money today, with electricity costing 10 cents a kilowatt hour or more during the winter.

As the days shorten into autumn, lights come on earlier in Maine homes. For the next six months, the lights will run longer, consuming more electricity and driving up the monthly electric bill.

Besides shutting off unnecessary lights, what else can a consumer do to cut the electric bill and save electricity?

A suggestion: replace inefficient incandescent lights with energy-efficient lights.

Just as an auto manufacturer lists a vehicle’s fuel efficiency in miles per gallon, a light-bulb manufacturer lists lighting efficiency in lumens per watt (LPW), or how much light the bulb produces for each watt of electricity that it consumes. The higher the LPW, the more efficient the light bulb.

The typical incandescent light bulb actually represents the lowest form of lighting technology and efficiency, producing 7 to 22 LPW (the figures do vary between light-bulb manufacturers). In comparison, the 48-inch fluorescent light bulb found in many offices produces 35 to 100 LPW, giving far more light for the same amount of electricity.

Manufacturers have improved the incandescent light bulb. A tungsten-halogen bulb will throw 14 to 22 LPW, perhaps slightly more light than will a long-life incandescent, but the tungsten-halogen bulb will burn between 3,000 and 3,500 hours — about four times longer than a cheaper incandescent bulb.

The reflector lamp represents another improvement to the incandescent bulb. The manufacturer coats the reflector bulb’s interior with aluminum to reflect light to a certain point, effectively multiplying the lighting effect since the light need not fill the surrounding area. Recessed and directional lighting often feature reflector lamps.

Light-bulb manufacturers make other bulbs that don’t rely on incandescent technology. The compact fluorescent bulb that appears in many hardware stores should glow about 10,000 hours and throw off 50 to 69 LPW, while the mercury vapor bulb that a homeowner can usually screw into a standard lamp socket will run 16,000 to 24,000 hours and throw off 31 to 63 LPW.

As far as energy efficiency, exterior lighting offers a few options that won’t work inside the home. Long a mainstay in fixtures that brighten doorways, incandescent lights cast their arcs only so far, often leaving dark shadows in which anything might lurk.

To brighten a blackened yard, a homeowner can install a high-pressue sodium lamp that will run 16,000 to 24,000 hours and cast 63 to 140 LPW, or perhaps a low-pressure sodium lamp with a shorter lifespan (10,000 hours) and a brighter bulb (100 to 183 LPW). Either lamp could be connected to a photocell that turns the light on at dusk and off at dawn.

A more energy-efficient system replaces the photocell with a motion sensor, a device that flips on the light whenever something moves within its electronic range of vision. Leaving an exterior light — even an efficient sodium bulb — on all night uses more electricity than would a system that activates only when it senses motion.

The motion sensor comes with a timer that can be set to leave the light on for a few seconds or several minutes. The sensor has one drawback, however: If even a skunk waddles through its “vision,” the sensor will turn on the light.

Some manufacturers now produce solar-powered exterior lights.

Interior lighting can be adapted to sensors that will turn a room’s lights on and off, depending on what the sensor detects. One sensor “listens” for sounds in a room, while another sensor searches for movement. A third sensor (an infrared unit) “sniffs” for body heat; this sensor would work poorly in a bedroom or in a house with too many cats.

That reliable standby, the household timer, can help save electricity by turning on a light just before someone arrives home (no need to leave a light running all day). A timer functions best as a security device that switches on and off at appropriate times to give a house that occupied-look.

Unfortunately, energy-efficient light bulbs cost more than incandescent bulbs, and many people avoid the higher initial price without realizing the long-term benefits:

An energy-efficient bulb will consume less electricity to cast the same amount of light — or produce more light from the same wattage. Substituting a lower-wattage efficiency bulb for a higher-wattage incandescent bulb will cut an electric bill, perhaps not a great amount, but by something. In the winter, every kilowatt saved represents a dime or more left in the homeowner’s pocket;

An energy-efficient bulb will run much longer than will a less-expensive incandescent bulb. The typical incandescent bulb found on supermarket or store shelves might last 750 hours, guaranteeing its replacement within the year. A mercury-vapor bulb will burn forever when compared with an incandescent bulb.