Energy Efficient Incandescent Lamps

Although incandescent lamps use more energy than other types of lamps to produce the same amount of light, there are some situations where they are appropriate. They have the sparkle and definition of sunlight and they are best suited for frequent on-off situations. The following are ways to reduce energy costs with incandescent lamps.

Krypton-Filled Long-Life Lamps

For hard-to-reach places where changing the lamp can be difficult, krypton-filled long-life incandescents are an excellent choice. Krypton-filled lamps will last as long as standard long-life incandescents, but use less electricity.

High Efficiency Incandescent Lamps

High efficiency incandescent lamps can yield substantial savings. For example, a new 67-Watt replacement for a 75-Watt lamp produces only 5% less light, yet uses 11% less electricity.

Ellipsoidal Reflector Bulbs

An ellipsoidal reflector (ER) lamp can be a wise replacement choice for a reflector floodlamp in a deeply recessed ceiling downlight fixture where 50% or more of the light may be trapped inside the fixture. The lower-powered ER lamp is designed to project more light out of the fixture than the floodlamp. A 75-Watt ER replacing a 150-Watt regular floodlamp often yields more light and uses half the power. Energy savings can be substantial (see Table 1). If you need more light, try a larger ER lamp, or a socket extender that brings the front surface of the lamp closer to the opening of the fixture.

With the Reflector lamp, light is trapped inside the fixture.
ER lamps project more light out of the fixture.

Notes: Savings are calculated to the nearest dollar. It is assumed that: lights are used 52 weeks a year, 60 hours a week; regular floodlamps are replaced when they burn out; both lamps will last about 2,000 hours (about 8 months at 60 hours a week); when purchased in quantity, a 75W ER lamp costs about 65 more than a 150W, R-Type flood, and this cost difference ($1 per lamp per year) is subtracted from the electricity cost savings.

Incandescent Recessed Downlight Ceiling Fixtures
Savings from installing 75W Ellipsoidal Reflector (ER) Bulbs to replace 150W Reflector Floods (R)
If your
cost per
kWh is:
Your dollar savings in electricity cost per year if you replace this
number of lamps:

Replacing Two With One

In many cases you can use a single, more powerful lamp where you now have two or more. The larger the lamp, the more efficient it is; higher wattage = more lumens of light per watt. (This is true for all except fluorescents.) For example, two 60-Watt incandescents (1,680 lumens) can be replaced with one 100-Watt lamp (1,800 lumens) that yields more light and saves 20 watts of electricity. (See Table 2 showing how various levels of wattage reduction translate into electricity cost savings.) A 20-Watt reduction saves 15 kWh of electricity over the life of a new lamp - enough to justify replacing lamps before the old ones burn out. Old lamps can also be used as temporary replacements in areas that are now over-lit.

Save by Substituting Lower-wattage Lamps
If your electricity
cost per
kWh is:
Annual electricity savings* if each replacement lamp saves:
$  9.36
*Assumes lights are used 8 hours a day, 5 days a week, 52 weeks a year (2,080 hours a year)

Tungsten Halogen Lamps

Tungsten halogen lamps have slightly higher efficiency, longer life and whiter light than standard incandescent lamps. For example, a 150-Watt PAR lamp can be replaced with a 90-Watt halogen lamp and can last up to three times as long as the standard PAR lamp. Similarly, a 75-Watt PAR lamp can be replaced with a 45-Watt halogen PAR lamp. Halogen A-line lamps (the classic light-bulb shape) use about 10% less energy than standard lamps. They are available in most of the common incandescent lamp shapes.