Green product watch: LEDs vs. CFLs 10/11
(This article is adapted from the October “2011 Guide to saving energy at home” in Consumer Reports magazine.)
Manufacturers of compact fluorescent light bulbs (CFLs) and light-emitting diodes (LEDs) make a lot of promises, from the bulbs’ brightness and light color, to their lifespan and energy savings. For several months the Consumer Reports lighting lab has put those claims to the test, and after 3,000 hours of testing, the results are in and have been confirmed by an outside lab. Watch video.
26 different CFLs and 10 LED models — a total of 360 bulbs — were tested. The tests focused on 60-watt equivalent CFLs and LEDs because those are the most popular types sold in the U.S. (Ratings are available to Consumer Reports subscribers.)
The tests showed that many of the problems of earlier CFLs and LEDs have been overcome: they do last longer and use less electricity than standard incandescent bulbs. In addition, all of the LEDs instantly brightened, even at frigid temperatures, and they all gave off a warm white light.
CFLs use about 75 percent less energy and last seven to 10 times longer than regular incandescent bulbs. But LEDs are the newest choice. They use even less energy than CFLs and are claimed to last for decades. And federal law is set to require most screw-in bulbs to be more efficient by 2014.
CFLs save money faster
It usually takes less than a year to recoup the cost of most CFLs, according to the tests, which are based on the bulbs being turned on for 3 hours a day. From that point on you're saving money by using less electricity, about $52 dollars per 60-watt equivalent over a bulb's lifetime.
Because of the high cost of LEDs, $20 to $60 per bulb without rebates, they can take four to 10 years to pay for themselves, based on the tests. Even at those prices, you can still save between $65 and $400 over the 18- to 46-year life of the LED compared with an incandescent bulb.
But you probably won't save money by switching from a CFL to an LED until the price of LEDs comes down. However, the tests revealed some other reasons that you might want to switch.
LEDs meet most of their claims
After 3,000 hours of testing, the best LEDs were still as bright as the incandescents they replaced. But only about half were as bright as promised. All the LEDs reached full brightness instantly, even at frigid temperatures, providing warm white light that was unaffected by frequently turning them on and off. Energy use matched or exceeded claims, and LEDs don't contain mercury (CFLs do in small amounts). Some LEDs dimmed as low as incandescents. But not all LEDs are good at shining light where you need it.
19 Consumer Reports staffers used six different LEDs at home for two weeks each and evaluated them using a questionnaire developed by sensory specialists. Their favorites were:
Philips AmbientLED, $40, best for table or floor lamps and ceiling fixtures; Several other brands were also high-rated in the tests. But staffers said they wouldn't buy any of them until prices drop.
EcoSmart LED Downlight, $50 (Home Depot), best for recessed and track lights; and
EcoSmart PAR38 Bright White, $45 (Home Depot), best for outdoor lights.
CFLs now have less mercury
The amount of mercury in the CFLs tested has dropped 60 to 75 percent, compared with the already low levels found in 2008, without affecting performance. Mercury helps CFLs produce light. And most CFLs contained less than 1 milligram of mercury. The one exception is the EcoSmart covered CFL, and even that has significantly less than Energy Star allows.
Given the test results, Energy Star could consider lowering the mercury cap below 5 milligrams. Nevertheless, spent CFLs should be recycled. Home Depot, Ikea, Lowe's, and some Ace Hardware stores will accept used bulbs.
Three of the CFLs tested, including the top-rated GE Energy Smart Saf-T-Gard spiral, have a plastic coating that contains mercury and any shards if the bulb breaks.
For CFLs, follow clean-up guidelines at www.epa.gov/cfl/cflcleanup.html. For LEDs, sweep up any broken bulbs and recycle them with other electronic waste because they contain semiconductors.
• Check store displays of lit bulbs to get a feel for their light quality. Related links
• Look at lumens — watts tell you only energy use. Lumens measure brightness. Look for at least 450 lumens in a CFL if you're replacing a 40-watt bulb, 800 lumens or more for a 60-watt bulb, 1,100 lumens for a 75-watt bulb, and 1,600 lumens or higher when replacing a 100-watt bulb.
• In R30 floodlights, look for a lumen count that is at least 10 times the wattage of the bulb you're replacing, 650 lumens to replace a 65-watt bulb, for example.
• To get the right color, use kelvins — the whiteness, yellowness, or blueness of light is measured by its temperature in kelvins. Incandescents produce a warm yellowish light with a color temperature of about 2,700K. At 3,000K the light is whiter and comparable to that of a halogen bulb. Bulbs at higher temperatures, with their bluer tones, can be unflattering indoors. Terms like soft white and warm white mean different things to different manufacturers.
• Note the CRI, or Color Rendering Index — the CRI indicates how accurately colors appear under the light, and ranges from 0 to 100, with daytime sunlight at 100. Most of the tested bulbs are in the low 80s; a few reached the upper 80s and low 90s. A CRI of at least 80 is generally recommended for interior lights, and differences of fewer than five points are insignificant.
• Read the package — As of Jan. 1, 2012, a Lighting Facts label must appear on the packages of most bulbs. It will show brightness, energy use, estimated energy costs, expected life, light color in kelvins, and, for CFLs, mercury content. Note: Only the information on Energy Star bulbs has been independently verified.
• Check for rebates and coupons — Visit www.dsireusa.org/incentives or www.energystar.gov to find utility rebates and search online for manufacturer rebates and coupons. Many are instant rebates, so you won't have to fill out any paperwork.
• Keep your receipts — The bulbs are supposed to last for years, so save the receipts and UPC codes. You'll need them to return a bulb to the manufacturer or retailer.
Consumer Reports 2011 Guide to saving energy at home. 10/11
Philips wins DOE’s lighting prize plus 10 million. 8/11
Guide to Greener Kitchens: Lighting. 8/11
LEDs star and LightFair but will consumers buy them? 5/11