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Energy-Saving Light Bulbs

Looking for the most energy-efficient light bulb? Not sure whether to go CFL or LED? Still using incandescent bulbs? Thomas Edison will forgive your move to energy efficiency.

UM Go Green has the light bulb breakdown. 

Compact fluorescent lights (CFLs), and light emitting diodes (LEDs) use about 25 to 80 percent less energy and last three to 25 times longer than the typical incandescent bulb (U.S. Department of Energy). To create the same amount of light, an incandescent bulb emits 60 watts of energy compared to 15 watts for CFLs and 12.5 watts for LEDs. 

Cost Comparison* 

 

LED

CFL

Incandescent

Projected lifespan

50,000 hours

10,000 hours

1,200 hours

Watts per bulb

10

14

60

Cost per bulb

$35.95

$3.95

$1.25

Kilowatts (KWh) of electricity used over 50,000 hours

300-500

700

3,000

Bulbs needed for 50,000 hours of use

1

5

42

Cost of electricity (at 0.10 per KWh)

$50

$70

$300

Total cost for 50,000 hours

$85.75

$89.95

$352.50

*Costs may vary. Source: Eartheasy Solutions for Sustainable Living

Benefit Comparison

 

LED

CFL

Incandescent

Long-lasting

x

x

 

High quality light

x

x

 

Cool temperature

x

 

 

Mercury-free

x

 

 

Efficient

x

x

 

Cost-effective

x

x

 

Environmental impact*

Low

Medium

High

*Replacing a single incandescent bulb with a CFL will keep a half-ton of carbon dioxide out of the atmosphere over the life of the bulb.

CFLs or LEDs?

While CFLs pay for themselves in less than six months (for LEDs, less than two years) and may be more cost-effective than LEDs, here are some of the limitations of this cheaper option: 

  • Sensitive to frequent on/off cycling, which wears down durability
  • Must be covered or shaded from outdoor elements
  • Contain small amounts of mercury, a toxic metal harmful to the environment and your health
Each year, an estimated 600 million fluorescent lamps are disposed of in U.S. landfills, amounting to 30,000 pounds of mercury waste. This is enough mercury to pollute every lake, pond, river, and stream in North America!
 
CFLs cause slightly more environmental harm than LEDs, but they are still a better option than the incandescent bulb, which uses more natural resources to generate electricity. We can reduce the environmental impact of lighting by choosing more efficient light bulbs. 
 
If you would like to calculate your current or estimated light bulb cost, click hereTo calculate LEDs' return on investment, click here