Philips LED lamps still at 100% after 25,000 hours

July 23, 2013

Two-hundred Philips LED lamps that have been running continuously for 25,000 hours (nearly three years) are still operating at 100 per cent lumen output, according to tests conducted for the US Department of Energy (DoE).


The 10W lamp won the DoE's L Prize in 2011 in the 60W replacement category, and at that time Philips said it expected to see lumen maintenance of 97.1 per cent at 25,000 hours - based on 7,000 hours testing of 200 samples.


When the lamps reached 25,000 hours of operation in April this year, the results exceeded expectations. Not only were they still running at 100 per cent lumen output, but the colour was stable (with less than 0.002 change in chromaticity according to the CIE 1976 colour diagram) and all of the lamps survived stress tests which had seen off two thirds of the CFL competitors.

The tests were conducted at the Pacific Northwest National Laboratory, in a specially designed facility kept at 45°C. The DoE's report said the results suggest that lighting manufacturers may be able to get away with diverting attention from testing lumen and colour maintenance, and towards other aspects of product performance.


The Philips lamp on test has since been superseded by lower wattage products designed to last even longer, and without the yellow phosphor outer surface, which proved unpopular.

The report said: ‘As this marks one of the first public opportunities to confirm actual performance of a high-quality LED product at 25,000 hours, it can serve as an indicator for the long-term potential for a well designed and constructed product, and validate the methods being used for extrapolating and predicting long-term performance.’


The DoE said it will continue to test a subset of the lamps, creating what it says will be ‘the only publicly available, third-party data set of long-term LED product operation’.


Its report said: ‘Depending on how the SSL market evolves, how the technology changes over time, and whether buyers and producers coalesce around well-designed products with strong lumen and chromaticity maintenance performance, these test results indicate it might be possible to pay less attention to lumen and chromaticity testing in the future, saving producers and buyers significant money, and allowing them to shift their attention to other luminaire performance attributes.’

For further information, please contact:

Jenny Heyes
Marketing Manager Philips Lighting Southern Africa
Telephone: 011 471 5056

About Royal Philips

Royal Philips (NYSE: PHG, AEX: PHIA) is a diversified health and well-being company, focused on improving people’s lives through meaningful innovation in the areas of Healthcare, Consumer Lifestyle and Lighting. Headquartered in the Netherlands, Philips posted 2012 sales of EUR 24.8 billion and employs approximately 115,000 employees with sales and services in more than 100 countries. The company is a leader in cardiac care, acute care and home healthcare, energy efficient lighting solutions and new lighting applications, as well as male shaving and grooming and oral healthcare. News from Philips is located at