I know regular light bulbs burn out, and so do CFLs. but do LED lights burn out too? And do they provide the same level of light throughout their life, or fade like incandescent lights do?
Answer from Green Energy Efficient Homes
LED lights do burn out, but at least in theory they should last far longer than incandescent or fluorescent lights. All lights are rated in terms of the average hours they can be left on before the bulb burns out. While the cheapest incandescent bulbs are rated around 500 hours, and better ones around 800-1,000 hours (and in many locations, standard incandescent light bulbs are not even available for sale any more), fluorescent lights are typically rated at 8,000 hours or ten times longer.
LED house lights meanwhile are supposed to last up to 100,000 hours, although the claims on product packaging are typically much lower, in the 25,000 to 50,000 range. I’m not sure if that is because manufacturers are hedging their bets, or if it’s that there are major quality problems that are bringing down the average, but still, even assuming a typical life of 25,000 hours, your LED lights would last you about 34 years if you use them an average of 2 hours a day. Even if you leave them on 24 hours a day, they should in theory last you almost three years!
One other consideration when considering how fast LED lights burn out is that an LED light bulb is made up of a number of individual Light Emitting Diodes. An individual LED may well last 100,000 hours, but it only takes one of those diodes failing before the bulb can be considered to no longer be working properly.
Compact fluorescent lights are typically rated at 8,000 hours but I have seen CFLs burn out much faster than that. One factor that leads to faster burnout of CFLs is their use in ceiling fixtures. CFLs are not ideally suited to ceiling fixtures, and tend to burn out faster there, for two reasons. First, they are meant to be positioned vertically, with the screw-on base either directly below or above the spiral coils of the bulb. In most ceiling fixtures they are positioned horizontally. Second,their life is shorted by heat, and an enclosed ceiling fixture will allow the heat to build up faster. The other thing I have noticed recently is that as prices have fallen in the last couple of yeras, we have seen a decrease in quality – you get what you pay for. I encourage you to always keep the receipts for any lights you buy – whether fluorescent, LED, or incandescent. If your incandescent or CFL or LED lights burn out well before their expected lifetime, you should take them back and demand a refund. The quality of newer bulb technologies will only improve if people fight back against cheap but poor quality products.
LED lights do burn out, but as I explain in my main LED house lights article, they typically start to fade long before that. In fact LED lights can dip down to less than 80% of their original brightness within 20,000 hours; the drop-off rate may be part of the reason manufacturers are toning down their claims of bulb life. I would submit that in almost every application, LED lights will fade to the point that they are no longer suited to their lighting task, and will be replaced for that reason before the burn out.
One bright point here is that LED lights are much less prone to wear and tear from frequent switching on and off, than are fluorescent lights, so if you do turn off lights whenever you leave a room (even if you might return very soon after), you’ll save energy while not damaging the lights.