Energy Star and the 25,000 Hour LED Limit

From the Energy Star website. Click to visit their page.

LED lighting is today's peak of mainstream energy efficient lighting (even though the industry continues looking at improvements to LEDs as well as alternatives). So you can imagine that Energy Star would want to encourage its adoption.

But smartly, Energy Star won't endorse just any old LED because, with consumer demand for low LED prices, a lot of companies have produced low quality LEDs to that demand. Unfortunately, this undermines public perception about how good LED lights can really be.

That's because a low quality LED might not last long (with rated lives of as little as 5000 hours); it might buzz or flicker when dimmed; it might lose its brightness or alter its color temperature (how "warm" or "cool" the bulb appears when lit) over time. This could definitely make people wonder why we should switch to LED lighting.

You can see, for instance, from this Energy Star image how a low quality LED can change after just 1000 hours of use. That's just one year of use in the typical home, and probably much less time in the typical office. Click here to see the Energy Star page on this topic.

Because of this, Energy Star has set certain standards for LEDs, so when you see their logo on an LED box, you'll know that the bulb is expected:

• To be at least as bright as the lighting it replaces, and to distribute light well
• To last at least 25,000 hours
• To maintain light output and color temperature
• To be at least as efficient as fluorescent lighting
• To provide instant light when turned on
• To not flicker when dimmed
• To not draw power when turned off

These days we've seen LEDs approaching $2 per bulb in some cases for a 60-watt incandescent replacement, but those bulbs are rated to only last 5000 to 10,000 hours while providing lower quality lighting. This effectively raises their "real" cost 2.5 to 5 times when compared to a bulb that lasts 25,000 hours. And the latter bulb will give you better lighting along the way. So in fact, the higher quality bulb may well cost you less in the long run while giving you a better experience.

This is why, at Lighting Supply, we include a wide selection of trusted brands like Philips and TCP as a foundation for our selection of LED bulbs.

We've seen an interesting situation come up based on the Energy Star label though. You see, LEDs cannot be tested for longevity in a traditional way. After all, you'd have to run them for 3 years straight to list a 25,000 hour rating if tested in real time. And since LEDs are based on digital technology, that bulb would be obsolete before you could list that rating.

So instead, LEDs are tested for 6000 hours (about 9 months) and then have their expected longevity determined by an algorithm. That lets a company project its rated lifetime without putting it through every last hour. Which is necessary because, with quality components, an LED could last far beyond 25,000 hours. In fact, we recently wrote about the L-Prize bulb from Philips and how it's still going strong after 40,000+ hours of real-time testing.

Based on this algorithm, a company could put an LED through testing and determine a rated life of much longer than 25,000 hours. Yet if they get it Energy Star certified, they can only list its life on the packaging as 25,000 hours. As we understand it, this is for consumer protection. Since the light hasn't gone through real-time testing, Energy Star doesn't seem to want to assume the bulb will last more than 25,000 hours, regardless of what the testing shows. This way, they're setting realistic expectations for consumers, who will certainly be happy if and when the bulb does last longer. And this drives more consumer confidence in the technology.

We recently ran into this in a practical sense when selling a particular LED bulb to a customer who had read about its 40,000 hour rated life. When he received the bulbs, he was surprised and disappointed to see 25,000 hours listed on the packaging. He contacted us to understand what was happening. It was precisely this matter of the 25,000 hour maximum listing on an Energy Star certified bulb. The spec sheet for the bulb continues to show 40,000 hours as the rated life, but the packaging only shows 25,000 hours.

Because of this, you may want to check on a company's spec sheet for Energy Star rated bulbs if you believe they're meant to last longer than 25,000 hours. Of course that sheet won't tell you how long the bulb will actually last, but it will tell you what the manufacturer expects. This will give you an idea of the quality of components they have used in the bulb.

---