Why Consumer Reports' lightbulb tests take years and years

Step inside Consumer Reports' lightbulb lab and you'll see rows of CFLs, LEDs, and halogen bulbs cycling on and off every two minutes. Over time this test shows our experts which bulbs can better withstand more frequent on/off cycles. But look above the lab's sink and you'll see a different test—two LEDs that have been on, day and night, for more than 13,500 hours and counting.

These Cree CR6 LEDs can replace 65-watt incandescent recessed bulbs and Cree claims they're designed to last 50,000 hours. That's more than 45 years when used three hours a day. In a span of 45 years it's possible you'll haul three dryers and five microwaves to the curb, according to data from the National Association of Home Builders, a trade group.

The CR6 downlight module is for 6-inch housings and costs about $45 online without rebates. HomeDepot's EcoSmart LED Downlight E26 Eco-575L is the same dimmable bulb and made by Cree. It's $25 and tops our Ratings in the flood/reflector category. Home Depot says it can last up to 35,000 hours. Why the difference in estimated life? Michelle Murray, a spokesperson for Cree calls it a "business decision."

Our tough tests on these bulbs continue and we'll keep an eye on the Cree LEDs above the sink. In the meantime, use our current Ratings to find the best energy-saving bulbs for any application.

—Kimberly Janeway