Bright Tomorrow Lighting Prize (L Prize)

August 3, 2011

Every year it is estimated that more than 425 million 60 Watt incandescent light bulbs are sold in the United States alone, representing approximately 50% of the domestic incandescent light bulb market. The traditional incandescent that has been the market staple for more than a century, but only uses 10% of its energy output for light and wastes the other 90% as heat. The DOE recognized that energy efficient alternatives need to made readily available and become the new standard for Americans.


The US Department of Energy (DOE) established a competition, the Bright Tomorrow Lighting Prize (L Prize) initiative to spur development of high-quality, high-efficiency LED replacements for the common light bulb. Established through the Energy Independence and Security Act of 2007, the L Prize challenged the industry to meet its very demanding requirements – ensuring that performance, quality, lifetime, cost and availability meet expectations for widespread adoption and mass manufacturing. 


Philips was the first and only company to officially submit and complete L Prize testing for a 60 Watt equivalent. Since the September 2009 submission, Philips LED has undergone comprehensive evaluation, including performance testing conducted by independent laboratories, field assessments with utilities and other partners, long-term lumen maintenance testing and stress testing under extreme conditions.


The Philips L Prize submission required a team of engineers, technology and lighting experts from around the company including Philips Lumileds in San Jose, CA, Philips Color Kinetics in Burlington, MA and Philips Lighting Systems and Controls in Rosemont, IL, working together in multiple locations to push the boundaries of LED technology. As the world’s leading provider of lighting solutions it took Philips several years and millions of dollars in resources to develop the 60 watt equivalent LED that not only met, but exceeded the DOE’s requirements for the L Prize. 


Requirements for the 60 Watt incandescent LED replacement, as laid out by DOE, include:

  • Efficacy of more than 90 lumens per watt, exceeding the efficiency of all incandescent and most compact fluorescent sources today, ranging from 10 to 60 lumens per watt
  • Energy consumption of less than 10 watts as compared to a 60 Watt incandescent
  • Output of more than 900 lumens, equivalent to a 60 Watt incandescent light bulb
  • Lifetime of more than 25,000 hours, which is 25X greater than a typical incandescent bulb
  • Color Rendering Index (CRI) greater than 90, which is a high measure of lighting quality
  • Color Temperature between 2700 – 3000 Kelvin, which is “warm” white light comparable to incandescent


The Results


L Prize Requirement

Philips Result

Luminous flux (lumens, lm)

> 900 lm

910 lm

Wattage (W)

≤ 10 W

9.7 W

Efficacy (lm/W)

> 90 lm/W

93.4 lm/W

Correlated color temperature (CCT)

2700 – 3000 K

2727 K

Color rendering index (CRI)

> 90



US lighting consumption
According to DOE, an LED replacement for the 60 Watt bulb could save 34 terawatt-hours of electricity per year, enough to power the lights of 17.4 million U.S. households and avoid 5.6 million metric tons of carbon emissions annually.


Additional details on the L Prize competition are available at