This LED Bulb Is Officially the Greenest Lightbulb Ever

This lightbulb is officially the greenest replacement for a 60-watt bulb. It’s a light-emitting diode—commonly known as an LED—bulb made by the Dutch company Philips, it clocks in at under 10 watts, and it’s a bright, Big Bird yellow when it’s not illuminated. It also won its makers $10 million in the Department of Energy’s L Prize competition, which sought “high performance, energy-saving replacements” for the incandescents most of us still use.

If consumers are worried they’ll be burned by buying this bulb, they shouldn't be: It was “probably the most tested lightbulb in history,” said James Brodrick, the Energy Department’s light program manager. As part of its application, Philips submitted 2,000 bulbs. Two hundred of them went through testing that determined that they met the contest guidelines: They had to be under 10 watts, produce “warm white” light (yes, there’s a technical way to measure that), and work with dimmer switches. Another bunch were subjected to high and low temperatures, humidity, vibration, and other stress-testing. Two hundred more went for “lumen maintenance” testing. (LEDs don’t burn out, like incandescents. Instead, their light dims over time.) To meet the competition standards, the bulbs would have to dim by no more than 70 percent over 25,000 hours of use. This part of the testing took the longest—the team left the bulbs on for 7,000 hours, or about nine and half months, before they extrapolated the amount of light the bulbs would maintain.

But all of those technical measures don’t matter if people don’t like the light the bulbs produce. Thirteen hundred of the bulbs Philips provided went into field assessments in places like Raley’s Supermarket in Sacramento, a McDonalds in Jackson, an art museum in Oregon, residences in Martha’s Vineyard, and a public housing apartment in New Hampshire. The Department of Energy reports that “the majority of respondents perceived the amount and color of light as ‘just right.’” The “vast majority” would also recommend the lights to other people.

The only problem? The bulb will likely be rather expensive. It won’t come on the market until 2012, and Philips hasn’t said how much it will cost. But the price could top $40.

That’s a lot to pay for a single bulb. But consider this: In 2010 an estimated 971 million 60-watt bulbs were installed across the country. If everyone switched to these more efficient bulbs, we’d save $3.9 billion in electricity a year and keep 20 million metric tons of carbon from shooting into the atmosphere. Plus, the 60-watt bulbs we use now generally last for only 1,000 to 3,000 hours, which means you have to change each lightbulb every year or two. If this new bulb lasts for 25,000 hours (and it could last for more), you could use it for about 35 years without buying a new one.