5 tips for choosing energy-efficient lighting

1) LEDs are incredibly energy-efficient, have long rated lives, are dimmable, generate little heat and are very small.

Light emitting diodes (LEDs) are the latest technology in the lighting world. As with fluorescent lights, you’ll want to take a close look at the color rendering index (CRI) and the color temperature of any LED. 

  • Color rendering index is a measure of any light source’s ability to render colors accurately. You want a CRI of at least 80. 
  • Color temperature, which is measured in kelvins, gives you an idea of what the light will actually look like. The higher the number, the bluer the light source. Incandescent light is around 2700K–3000K. That color temperature in an LED typically looks very natural in the home. Avoid LEDs that are much above 4000K, unless you prefer the look of a very “cool” light.   

2) Use lumen output to choose a LED.

Some LEDs on the market claim to be incredibly efficient—and they are, in that they use very little energy. However, it’s no use replacing inefficient incandescents with LEDs if you mistakenly select an LED that doesn’t emit enough light.

Most people judge light output by watts (energy consumption), but for energy-efficient sources, this is an inadequate measure. What you’re really looking for is lumens (light output).

Use this chart to figure out how many lumens you’ll need in an energy-efficient light:

Incandescent Bulb Wattage Approximate Lumens
40W 360 lumens
60W 615 lumens
75W 960 lumens
100W 1100 lumens

3) Fluorescent light is one of the most efficient lighting sources.

For the minimal amount of energy consumed, fluorescent lights give off a surprising amount of light output. And if the word “fluorescent” makes you think of unpleasant, slightly blue office lights, think again. Fluorescent lighting has come a long way since it was invented in the 1930s.

Fluorescent lamps typically are available in “warm white,” “neutral white,” “cool white” and “daylight.” Most people prefer “warm white” for the home, as this is most similar to the familiar yellowish glow of the incandescent light.

  • If you’re buying fluorescent light bulbs for your home, find bulbs with a color rendering index greater than 80 and a color temperature of 3000K or less.
  • Also, select fixtures with instant-start electronic ballasts to make sure you have a light that will turn on without flickering. Instant-start electronic ballasts will also prevent you from ending up with a fixture that emits an annoying humming sound.
  • Get more selection tips from this Ask a Pro answer with architect David Bergman.

4) Incandescent light is the least energy-efficient lighting.

The federally mandated incandescent phaseout has already largely occurred, though it is still possible to find these bulbs.

Incandescent bulbs create light by heating a metal filament wire until it glows: not exactly brilliant technology. That being said, many people prefer the warm glow of incandescent bulbs over energy-efficient alternatives.

  • If you can’t part with your incandescents, be sure to install dimmers to optimize their efficiency. If you dim a bulb by just 25 percent, you’ll save 20 percent in energy costs and extend the life of the bulb. 
  • Although incandescent bulbs are the least expensive to buy, note that they are typically more expensive to operate, due to incredibly short life spans and relative inefficiency.

5) Halogen and xenon lights are a bit more efficient than the standard incandescent.

By adding halogen or xenon gas into the glass envelope of an incandescent bulb, the rated life of the bulb is increased.

  • A typical halogen lamp has a rated life of 2,000 hours, and a typical xenon lamp has a rated life of 10,000 hours.
  • Both halogen and xenon light bulbs are dimmable.
  • Halogen light is often described as “crisp” and “white”; it is cooler in appearance than xenon light.  

Read our buyer's guide to energy-efficient bulbs