LED bulb longevity report

Now that I’ve had a couple of LED bulbs burn out, I can actually give an LED bulb longevity report.

I’ve been buying LED bulbs since 2010, and now I’ve lost three of them. It’s a little disappointing, but two of the bulbs were Philips 420240 bulbs, which are no longer on the market. The first 420240 failed completely within a couple of weeks of getting it, and I exchanged it for a Cree. The second 420240 lasted a shade over two years. Clearly the 420240 just wasn’t a very good bulb, and it accounted for my first LED bulb mortality.

My other failed bulb is one of the early 40W equivalents I bought at either Lowe’s or Home Depot in 2010 or early 2011. So I got about four years out of that one, which is better than Philips at least.

Both the store-brand bulb and the second 420240 failed the same way: They would operate but occasionally shut themselves off, sometimes only for an instant, or sometimes for minutes at a time, before coming back on. After a few weeks of this intermittent operation, they failed completely. So both gave ample warning they were on their way out. The intermittent operation was a bit irritating, but if it’s the only bulb in a room, I suppose intermittent operation would be better than total failure.

I’m not ready to write LEDs off just yet. I have bulbs older than both of these that still work fine. And today’s LEDs are cheaper and more efficient than either of these bulbs ever were.

My experience with CFL bulbs was generally good, except with Sylvania bulbs, which never worked out for me. But Ecosmart and Feit Electric CFLs did well for me. I still have a few of each, purchased between 2008 and 2010, that work fine.

Over time, I came up with some tips to increase CFL life expectancy. It will help LEDs too.

I can get a two-pack of 40w equivalent Ecosmart LED bulbs at Home Depot for $10. They use 6 watts to give off 450 lumens, which will be adequate to replace the two bulbs I lost. I like Cree bulbs a lot, but I also like the idea of using 50% less power so I’m leaning that direction, especially given that Ecosmart’s CFL bulbs served me well.

I also have a couple of Philips Slimstyle bulbs, but given my poor experience with the 420240, I’m not inclined to buy any more of them.

What the math says

Due to the amount of money involved, people tend to get very emotional about lighting. It makes sense in a way; incandescent bulbs used to come in packs of four that cost a dollar, so when one burned out, you weren’t out much money, and it wasn’t very clear what the bulb actually cost you every month to run. Newer forms of lighting are a lot more expensive and you need special equipment like a Kill-a-Watt and a computer to figure out how much they’re saving you. Those LED bulbs that burned out on me cost $15 and it’s not clear how much, if anything, they actually saved me. In the early days, part of the promise of LED bulbs was that they would last a decade or more. They needed to last a long time in order to pay for themselves.

But I’m going to try to look at the cold, hard numbers. I’m comparing LEDs to CFL bulbs because with incandescents the math isn’t even close. LEDs win by a long shot.

My experience with LED bulbs isn’t a large enough sample size to be statistically significant, but I count 27 working LED bulbs in the house. That means I’ve bought a total of 30 LED bulbs, so my failure rate is right at 10 percent.

My college statistics professor says that’s not worth worrying about. The better question in my case is whether my bulbs paid for themselves.

On average, the DoE estimates we spend about 14 percent of our electric bill on lighting. I spend about $1,500 a year on electricity, so that means I spend $210 a year keeping the lights on.

Today’s LEDs are 30% more efficient than competing CFL bulbs. Older LEDs were only about 10% more efficient. We’ll split the difference since I have a mix of old and new bulbs. At 20% efficiency, that means LEDs are saving me $42 a year. Since I have 29 bulbs–remember, I exchanged one–each bulb is saving me $1.45 a year.

Today the economics are a little different because the bulbs are cheaper. I pay $5 per bulb now, which is $4 more than a CFL would cost. If the bulb is saving me $1.45 a year, I need it to last 2.76 years. I have several LED bulbs that are that old.

The costlier the bulbs are, the longer they need to last. The bulbs that failed cost more: around $15. CFL bulbs cost a bit more then too, so the price difference was about $13. That means the LED bulbs needed to last 8.97 years to pay for themselves. Neither of those did, of course.

Warranties matter now

I count 50 bulbs in my house. When bulbs are worth less than a dollar apiece, it’s not worth fretting over. When bulbs cost $5-$10 apiece, suddenly we’re talking an investment. It is an investment–an investment in power savings–but it’s less tangible than a kitchen range or a washing machine even though the cost is similar.

Part of me frets over having spent hundreds of dollars on LED bulbs. But I’m a technologist, an early adopter, and this is a technology that interests me. If people like me hadn’t run out and bought LED bulbs in 2010, would we have the nice bulbs we have today? Maybe not.

Back when you could buy a 4-pack of light bulbs for a dollar, we kept a stash of them in the closet and we just counted on changing a couple of bulbs every month. I stopped doing that years ago, because by the time a bulb burns out, there’ll be a better bulb available, one that’s cheaper and more efficient.

In 2008, I started writing dates on bulbs because I realized I didn’t really know how long the bulbs were lasting. The first CFL bulbs I bought seemed to last a long time, but I had a point in time where the Sylvania bulbs I was buying weren’t lasting. The LED bulbs I was buying in 2010 and 2011 were replacing undated bulbs, and today the bulbs I’m replacing have dates from 2008-2010 on them.

Since I need bulbs to last three years to be worth the cost, I figure I need to be doing three things:

1. Buy bulbs that have at least a three-year warranty. Longer is better, but I expect three years from now the bulbs will be more efficient so I’m mainly concerned about the bulbs lasting long enough to pay for themselves. When the payoff is 2.76 years, a three-year warranty is sufficient. If I were still paying more than $10 for bulbs, I’d want that 10-year warranty.

2. Write the date of purchase on the bulb, which is a practice I’ve never regretted starting.

3. Keep the warranty information, the receipt, and UPC from each bulb. I have the receipt from that Philips bulb but nothing else, so I don’t know how to make a warranty claim. I can afford to just buy a $5 bulb to replace it and save the paperwork this time, and that’s less stressful. And while newer bulbs probably will be more reliable than the old ones, saving the warranty papers makes sense. Like it or not, lighting is an investment at this point. Most of us would save the information we needed in order to make a warranty claim on a $300 television; modern lighting is a comparable commitment when you figure each room needs 2-3 of them, on average. The difference is that the lights save you money, which may not be the case with that TV.

One thought on “LED bulb longevity report

  • March 6, 2015 at 8:02 am

    Record keeping — perfect job for a scanner and a hard drive!

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