Philips has won a category in the US government's competition to demonstrate the highest efficiency high quality lighting.
In 2007, the US Energy Independence and Security Act directed the Department of Energy to establish the 'Bright Tomorrow L Prize' competition.
The competition has three categories:
21st Century Lamp, a partially-defined category whose initial parameters were bettered by Cree this week.
60W incandescent bulb replacement, now won by Philips.
PAR 38 halogen lamp replacement competition, which has been postponed.
In each case, both efficiency and light quality targets were set.
For the 60W replacement, the L Prize demanded: luminous flux of >900 lm, power consumption under 10W, efficacy over 90 lm/W, colour temperature from 2,700 to 3,000K ('warm white'), and colour rendering index above 90.
The Philips bulb hit 910 lm, 9.7W, 93.4 lm/W, 2,727 K and CRI=93.
"Submitted in 2009, the LED bulb completed 18 months of field, lab, and product testing to meet the requirements of the L Prize competition," said Philips. "If every 60W incandescent bulb in the US was replaced with the 10W winner, the nation would save about 35TWh of electricity, or $3.9bn in one year, and avoid 20 million tonnes of carbon emissions."
Lumen maintenance after 25,000 hours is predicted to be 99.3% (95% confidence, 200 units) compared to the 70% prize requirement.
The firm expects to have the winning lamp on the shelves "as soon as early 2012".
Like some of Philips' production LED light bulbs, the prize winner uses remote phosphors with royal blue (450nm) emitting Rebel LEDs from Philips-owned Lumileds providing the light.
Some of the blue light is converted to other colours to fill out the spectrum for white emission by phosphors in the outer shell of the bulb.
In January this year the Department of Energy suspended the L Prize PAR 38 category.
"The proposed modifications to the PAR 38 competition requirements will integrate lessons learned to date from the 60W replacement competition," said the DOE, which has yet to re-open it.