The L Prize (aka the Bright Tomorrow Lighting Prize) is a competition run by the United States Department of Energy aimed to "spur lighting manufacturers to develop high-quality, high-efficiency solid-state lighting products to replace the common incandescent light bulb"^[1]. While Philips has marketed the similar 12-watt Endura LED lamp, it does not meet the L-Prize efficiency and power requirements.^[2]

The competition offers two prizes for the replacement of two types of bulb, an A19 60-watt incandescent light bulb and a PAR 38 halogen incandescent bulb. The prize fund for the 60 W replacement is up to a maximum of US$10 million and for the PAR 38 up to US$5 million.^[3] There is a third category, yet to be defined, called the 21st century lamp.^[4]

The competition has set out various qualifying requirements for the replacement bulbs summarized in the table below:

Winner[link]

It was announced on 3 August 2011, that the winner of the 60 W replacement bulb competition was a bulb made by Philips.^[5][6] The winning bulb was a LED lamp using less than 10 watts and emitting the equivalent amount of light as a traditional 60 watt incandescent bulb. That amounts to an 83% energy savings. It was announced that Philips would be given the US$10 million cash prize.^[5][6] The bulb was released commercially in February 2012 through several online sellers; however the widespread launch at retail stores was not until Earth Day, April 22.^[7] Although the subsidized price was expected to be $22 in the first year, $15 in the second and $8 in the third, the bulb was initially selling for $50-$60 (without rebates) as of April-May 2012. Somewhat less efficient competing LED bulbs were selling for less than half that.^[8]

Comparison of Philips LED bulbs intended as screw-in replacements for the 60-W incandescent bulb. The original 12-watt Philips A19 "Endura LED" bulb is on the left, and the somewhat brighter 10-watt L-Prize bulb on the right.

The L Prize bulb was made to generally be a compatible replacement for a standard A19 light bulb (which has 1-inch Edison screw base). Although the bulbs appear yellow when switched off, they produce a "warm" white light (2700°K color temperature) when illuminated. The consumer product was labeled as 940 lumens, slightly higher than the one tested by the DOE.

References[link]

External links[link]

• www.lightingprize.org - L Prize website.
• The Changing Shape of Light - CBS Evening News
• The $10 Million Lightbulb - Time magazine article.
• Is This the Light Bulb of the Future? - New York Times article