The lighting industry improved and miniaturized fluorescent technology so the bulbs could be made to fit into regular light bulb sockets. They last 10 years and use about a quarter of the energy of traditional light bulbs.
This technological revolution happened 20 years ago. The trouble is the consumer revolution never came with it. The compact fluorescent light bulb (or CFL) is found in less than 6 percent of U.S. households.
Then came Wal-Mart.
Wal-Mart recently announced that it will seek to put compact fluorescent light bulbs into 100 million homes. A cacophony of controversy both in print and on the Web has been rising ever since. There appear to be more opinions than bulbs.
Each CFL saves $30 to $40 in energy, which translates into about 1,300 pounds of carbon dioxide and 20 pounds of sulfur from coal-fired power plants. What's not to like?
Plenty, say many consumers, who complain about fluorescents' headache-inducing flicker, unflattering color and annoying buzz. We've all experienced the horrors of a buzzing, flickering, ghostly fluorescent that makes you feel like you're trapped in a Frankenstein movie. Who'd ever voluntarily introduce the torturous devices into their own home?
Experts counter that the stereotypes associated with fluorescents are a thing of the past. It is merely ignorance that keeps the fluorescent stigma alive. Who's right?
I admit that before writing this article I thought I knew all that needed to be known about fluorescents. But I found the topic has more twists than a mountain road. Let's see if we can shed some light on it.
Most fluorescents sold today for residential applications are called compact fluorescent bulbs. These bulbs resemble traditional incandescent light bulbs in shape and size and can be screwed into the same sockets. CFLs were made possible by the development of electronic ballasts, which have largely replaced the old magnetic ballasts, and many incremental improvements in fluorescent technology including cost reduction, better gases and improved manufacturing techniques.
Color and heat
Incandescent bulbs are known for creating warm, comfortable color that is pleasing to the eye. And no wonder: These bulbs burn very hot, in many ways emulating our most ancient artificial light source, fire.
Unfortunately the warm glow from incandescent bulbs, their best quality, is also their biggest problem. When you burn power in any light bulb, the electricity is transformed into either heat or light. The more heat you have, the less light. Incandescent bulbs produce a lot of heat and only a little light, making them the gas guzzlers of the lighting world.
Since lighting represents 15 to 25 percent of a typical household's electricity bills, it really adds up. The heat produced by incandescent bulbs also increases cooling bills in the summer.
That same heat is also what makes them burn out so fast -- the average bulb lasts 750 to 1,000 hours compared to fluorescent's 10,000-hour usage.
With fluorescent bulbs, most of the electricity is translated into light, with very little loss in heat -- but the light is bluish and ghostly, right?
Yes and no. Fluorescents use phosphor instead of a burning filament to create light. Back in the day, the phosphor used for fluorescent bulbs was very white and of limited spectrum. Compared to incandescent, the light seemed bluish. Now, quality residential fluorescent bulbs contain a number of different phosphor gases with a range of colors that increase the spectrum of color available.
CFLs are now available in an assortment of color ranges. The cooler, whiter shades are more energy efficient and provide better contrast for reading and other tasks, so they work best in reading lamps, kitchens, garages and offices. Warmer-colored bulbs are better in bathrooms, where makeup is applied, and in places where softer ambient light is desired, such as family and dining rooms.
The best way to evaluate color is based on the temperature of the light, which is done on the Kelvin scale. Unfortunately, many manufacturers do not provide this information on the consumer packaging, preferring a shorthand that varies among brands.
In side-by-side tests, people cannot distinguish the difference in fluorescent and incandescent light unless they see the bulb. However, when evaluated on a spectrograph, the range of colors varies between the two, with fluorescents tending to peak sharply at certain wavelengths. This translates into perceived color variation between objects seen under incandescent versus fluorescent light, which can be important for application of makeup or other color-sensitive uses.
Color rendering is usually evaluated based on the Color Rendering Index (CRI). For color sensitive areas, use bulbs with a CRI of 80 or higher.
Noise and flicker
Back in the bad old days of magnetic ballast fixtures, fluorescents used to buzz like wasps and flicker like old movies. Did I say bad old days? Magnetic ballasts are still common in offices, garage fluorescents and really cheap fluorescent fixtures.
Electronic ballasts have largely replaced the magnetic versions in quality fluorescent fixtures and in all CFLs. So, make sure you get a quality fluorescent fixture and quality bulbs and you will probably not notice any noise or flicker. GE, Philips and Sylvania all make quality bulbs, and an Energy Star label (www.energystar.gov) is a great recommendation.
The only caveat is that towards the end of their life, fluorescents do not go out with a bang like incandescents do, but a whimper -- sort of a humming flickering whimper that reminds us of the loud flickering fluorescents of yesteryear. Replace the bulb and all is well again. It also takes a CFL a few seconds to warm up, so they may flicker a bit during start-up.
It used to be fluorescents did not work with dimmer switches. Those days are past. However, you must choose a CFL bulb that is made for that purpose. Dimming fluorescent bulbs requires electronic ballasts that accept voltage variation. Check the package before you buy; if it doesn't mention dimming, it won't work with a dimmer switch.
Mercury and disposal
Fluorescent bulbs use a small amount of mercury in their manufacture. This has caused some people to question their environmental credentials. However, when comparing the mercury contained in fluorescent bulbs to the mercury discharged into the air by coal-burning power plants (which work all the harder for incandescent lighting), the equation nets out in favor of fluorescents.
Nonetheless, CFLs should not be thrown into the garbage. They should be brought back to the store where purchased or brought to a recycling center for proper recycling.
Cost and kickbacks
Fluorescents use about a quarter to a third of the energy used by incandescents to produce the same light. In addition, since fluorescents last more than 10 times as long, the economics are wonderful. PG&E also offers rebates on CFLs, further reducing their store price.
I recently bought a pack of three for $1 each. Expect to save $30 to $40 for each bulb you buy, with a corresponding reduction in greenhouse gas production and resource depletion.
The California Energy Commission estimates that if every household in California replaces one incandescent bulb with one CFL, consumers in the state would save $74.7 million a year, reduce garbage by 110 million bulbs and keep 974 million pounds of carbon dioxide out of the air.
How do I choose?
Nobody wants to become a lighting expert just to choose a light bulb. Environmental Defense (www.environmentaldefense.org) has put together a good Web site to help you chose CFLs based on location, wattage and other factors. Once you've chosen your bulbs, you won't have to worry about buying more until 2017.