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CFLs vs. LEDs: The Better Bulbs

Energy experts agree that the incandescent bulb is rapidly becoming a thing of the past. In fact, in 2007, Congress passed the Energy Independence and Security Act, which requires that all light bulbs sold on the market have a 30 percent increase in efficiency over today’s standard incandescent bulbs by 2012 to 2014. Though the new law won’t prevent you from using incandescent bulbs you already own, it does mean that stores will only carry more efficient bulbs that meet those standards from that point on.

You don’t have to wait for 2012 to begin replacing your incandescent bulbs with more energy-efficient compact fluorescent light bulbs (CFLs) or light-emitting diode bulbs (LEDs). Lighting can account for up to 20 or 25 percent of a home’s energy costs, so switching can result in savings on your monthly energy bill.

But LED technology is fairly new, and both CFLs and LEDs have advantages and disadvantages. Which do you choose, and for what uses?

Why Abandon Your Incandescents?
Invented by Thomas Edison in last quarter of the 19th century, modern incandescent electric light bulbs have been lighting much of the world for more than 100 years. Incandescent bulbs are lit by heating a wire tungsten filament until it begins to glow. Because approximately 90 percent of the energy generated in these bulbs is heat instead of light, they are extremely
inefficient. The average incandescent bulb has a lifespan of about 1,500 hours—a fraction of what you can get from a CFL or LED bulb.

Halogen lights are a more efficient form of incandescent lighting because they last longer; however, they get hotter than regular incandescent bulbs and pose fire and burn hazards.

For nearly every incandescent bulb still in use today, there’s a CFL or LED bulb that can replace it—saving energy and curbing carbon emissions. If you still have incandescents at work or home, it’s time to send them back to the Dark Ages.

CFLs: The Better Bulbs
CFLs (and fluorescent tube lights) are lit by an electric current that is sent through a tube
containing argon and a small of amount of mercury gases. This in turn generates an
invisible ultraviolet light, which then stimulates a fluorescent coating on the inside of the tube, producing visible light.

PROS: Longevity—With an average lifespan of approximately 10,000 to 15,000 hours, a CFL bulb lasts about ten times longer than an incandescent bulb—which means they need to be replaced less often, making them convenient for those hard-to-reach light fixtures and lamps.

Efficiency—“CFLs are about four times more efficient than the equivalent wattage of incandescent bulbs,” says Naomi Miller, the senior lighting engineer at the Pacific Northwest National Laboratory in Portland, OR. “So if you take the wattage of the CFL and multiply it by four, that equals the incandescent bulb you would replace. So, for example, a 15W CFL is roughly equivalent in light output to a 60W incandescent bulb.” According to the Environmental Protection Agency (EPA), if every household in America replaced just one incandescent bulb with a CFL, the energy saved would be enough to light 3 million homes and prevent greenhouse gas emissions from the equivalent of 800,000 cars.

Price—CFLs have dropped dramatically in price since they were first introduced to the market in the 1980s. They still cost a little more than incandescents; however, they will pay for themselves after a year or two of use (see box at left). Because they last so much longer than incandescents, you will continue to see savings on your energy bills throughout the life of the bulb.

CONS: Mercury concerns—Many people are concerned about the mercury in CFLs, and with good cause: mercury is a neurotoxicant. The amount in a CFL bulb, however, is smaller than the tip of a pencil. Widespread use of CFL bulbs instead of incandescents will actually reduce the amount of mercury released into the atmosphere, since the main source of mercury emissions are smokestacks from fossil fuel burning power plants, according to the EPA. CFLs pose little risk to your family if they break, but proper clean-up is important (see below).

Some usage limitations—CFLs are not dimmable, and they are not efficient in recessed lighting, where they waste about half of the energy they produce. To maximize their efficiency, avoid exposing them to extreme temperatures.

BEST USES: Many experts view CFLs as a placeholder for LED lights, because LEDs are even more efficient. Currently, CFLs come in more shapes and sizes than LEDs, but with ever-improving technology, many scientists think LEDs will be competitive within two to three years.

For the time being, CFLs are the best replacement for incandescent bulbs in most situations; just make sure they are disposed of properly at the end of their life cycle.

LEDs: The Future of Lighting
LEDs were first introduced to the market in 1962. They work by the movement of electrons through a semiconductor material. Initially, LEDs only emitted red light, so their uses were limited to indicator lights and lab equipment. Now, however, they are available in the visible, ultra-violet, and infrared spectrums, which means they now have a much wider variety of uses, including inside your home.

• PROS: Longevity—With a lifespan of approximately 25,000–35,000 hours, an LED bulb lasts 2 to 4 times longer than a CFL, and 25 to 35 times longer than a standard incandescent bulb.

Efficiency—While incandescent bulbs and CFLs generate most of their energy in heat, LEDs are cool to the touch—which translates into less wasted energy. It also means your air conditioner won’t have to run as high in hot weather. LEDs are more efficient than even CFLs: A 16.5-watt LED bulb is equivalent to a 20-watt CFL and a 75-watt incandescent. According to the US Department of Energy, adoption of LED lighting over standard incandescents over the next 20 years will prevent 40 new power plants from being constructed, generate more than $265 billion in energy savings, and reduce lighting electricity demand by 33 percent in 2027.

Other benefits—LEDs have other advantages over incandescent lights, including a smaller size and greater durability and reliability. Unlike CFLs, LEDs can also withstand extreme temperatures, and they do not contain toxic mercury.

Cons: Limited usage—LEDs only produce light in one direction, which make them great for
recessed lighting, but not so good in lamps and light fixtures intended to light up an entire room or area. (For example, in many lamps, an LED bulb will end up aimed at the ceiling, rather than offering the 360-degree glow of a CFL or incandescent.)
Like the first-generation CFL bulbs, most LED bulbs don’t illuminate instantly when they’re turned on. And it may be difficult at this time to find LED bulbs as bright as the brightest CFLs.

Color quality—Some users may find LED light a bit stark. “LEDs are most efficient when they emit a blue-white color, but many homeowners prefer a warmer (yellower) color of light,” notes Naomi Miller. When selecting an LED bulb, look for a ‘Lighting Facts’ label on the box, she says. It includes a spectrum bar that will indicate whether you’ll get a yellowish or bluish light.

Expense—According to Miller, “There are good LED products starting to be available, but they may be very expensive, costing $25 to $100 per bulb. It may be a year or two before the product quality improves and the cost comes down.”

BEST USES: LEDs are great for recessed and outdoor lighting, or lamps that produce a focused beam of light. They also make great indoor and outdoor holiday lights. They are not yet ideal for light fixtures and lamps intended to illuminate large areas of your home.

The Bottom Line
With their high efficiency and lack of toxic mercury, LEDs are the wave of the future, though they’re not yet ready to replace every incandescent. If you don’t mind their higher price tag (for now), buy them for the suggested “best uses” above. For the rest, use CFLs, and be sure to dispose of them responsibly when they wear out. That said, keep an eye on rapidly expanding LED technology—it won’t be long before they’re the bulb of choice for your every lighting need.

Victoria Kreha

Bulb Disposal

Incandescents and LEDs: At present, we don’t know of any recycling efforts for incandescent and LED bulbs, except holiday lights. Check with your local solid waste authority to see if you have local options. accepts incandescent holiday lights for recycling during the fall and winter months.

CFLs: In many states, it is actually illegal to throw CFLs out with your regular trash, so make sure they are recycled properly. Many home improvement stores, such as Home Depot and IKEA, have take-back programs for CFLs, and cities and counties often have recycling centers where you can take used CFL bulbs. Call your local solid waste authority or visit to find a recycling program near you. You can also order a CFL recycling kit from If a CFL breaks in your home, be careful cleaning it up, to avoid exposure to the trace amounts of mercury inside. The EPA recommends clearing children and pets out of the room, then airing out the room for at least 15 minutes. Pick up the glass using a towel or sticky tape. Wipe the area with a damp towel, and seal the towel or tape in a glass jar or plastic bag, and dispose.


Save Energy, Save Money with CFLs and LEDs

  Incandescents CFLs LEDs
Watts consumed
(to achieve equivalent brightness)
75W 20W 16.5W
Avg. lifespan (hours) 1,000 hours 10,000 hours 25,000–35,000 hours
Avg. cost per bulb $0.50 $5.00 $25–$100
Annual operating cost $8.87 $2.37 $1.95



More green-living articles from the Green American »

Article Summary

Replace incandescent light bulbs with CFLs and LEDs.

CFL and LED bulbs are more efficient, so you’ll save money on your energy bill.

Help reduce your home and office global warming
footprint and conserve energy.

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