Can a Product Last Too Long?

December 21, 2011 - A funny thing happened on the way to a new ENERGY Star Lamp program specification – a discussion on just how long our new LED light bulbs should last.

The question popped up at the U.S. EPA's stakeholder meeting I attended recently, held to discuss the draft specification for a new ENERGY STAR program to replace the current LED and CFL light bulb programs. The meeting was very well attended (approximately 50 people in person and over 100 more attending on-line). As described in a recent blog, Turning a Technology-Neutral Eye Towards Efficient Light Bulbs, the EPA would like to publish a single technology-neutral light bulb specification. It's an approach that's worked well in the past (i.e. ENERGY STAR television program) and reduces consumer confusion when multiple technologies are used for the same application.

While the one-size-fits-all goal works with many portions of the lamp spec - luminous efficacy (lumens/watt), color temperature, color rendering, dimming requirements, and others - an area that generated a great deal of discussion in the meeting was the harmonization of the minimum required lifetime of CFL and LED lamps. The new minimum proposed is 10,000 hours (raising the current CFL minimum from 5,000 hours but reducing the current LED minimum specs from 25,000 hours).

So, why degrade a new technology's reliability whose benefits include a very long lifetime? The EPA recently heard from some stakeholders that lowering the LED lamp lifetime to 10,000 hours could allow cost-reducing design changes, fueling a faster market transformation. The EPA calculates that a 10,000 hour bulb and a 25,000 hour bulb correspond to 9.1 year and 22.8 year lifetimes, respectively, which is a long time in either case. Also, it's a fair bet that LED lighting technology and efficiency will improve within the next decade and so the EPA is wondering whether it makes sense to require the longer 25,000 hours. This could result in the use of older technology, less efficient LED lights in consumer's homes for up to an additional 10 years or more, compared to using a 10,000 hour bulb.

But also during the meeting, a number of major lighting manufacturers disagreed with the notion that reducing the lifetime of the bulb alone would have a major effect on reducing the cost. So, without a significant cost advantage, does it make any sense to degrade an LED bulb's exceptional quality and reliability performance? It seems wrong somehow to allow an inexpensive weak link, such as the use of under-rated driver components or poor thermal design, to lead to the premature disposal of more costly and longer-lived components such as the LEDs. Additionally, a longer life bulb would reduce the impact on landfill, or, potentially impact the manufacturers' costs to recycle dead bulbs associated with extended producer responsibility programs being implemented in some European countries. The EPA is currently asking for more data to reach a decision on the issue.

Stay tuned. I'll report back on the ENERGY STAR lamp specification when the final draft is published in early 2012.

*with an average usage of 3 hours a day