A few years ago, it seemed like every major news outlet and magazine had a front page story dedicated to the worldwide transition from old-style incandescent lights to fluorescent lights. This was likely in large part due to the decision of many world governments to not only encourage the phase-out of incandescent lights, but to actually outright ban them. Despite the controversy this raised in Canada and other countries, the recent forced transition in 2014 seems to have gone rather seamlessly for Canadians, Americans, and the rest of the world. Nowadays, just about every light fixture in North America has a CFL (compact fluorescent light–the little swirly-looking ones) bulb installed.
But in the last couple years, LED bulbs designed for home use have started to creep onto the scene. They certainly haven’t made the same splash that CFLs did, but they are starting to draw attention. Even major continent-wide retailers like Home Depot, and worldwide furniture manufacturer Ikea, have started to aggressively advertise and sell LED-based bulbs. So why is this the case? After all, the CFLs that most of us have just gotten used to are pretty efficient and last quite a long time. Given how pricey LED bulbs can be–anywhere from $5 to $20 or more a piece–are they worth the money? We decided to find out. Here’s some information about what LED lights are, and what makes them worth your while.
LED stands for “light-emitting diode”
LEDs produce light by passing electricity through a semiconductor–material that is less conductive than something like metal wire, but more conductive than insulators like glass or wood. Layers of semiconductor are sandwiched together, and when energy passes through these layers, electrons–the stuff that electricity is comprised of–get excited and release light. You aren’t alone if this explanation seems a little confusing; LEDs are actually fairly complex little pieces of tech. One bit of evidence of this complexity is how long it took to discover the technology behind LEDs: while experimental incandescent and fluorescent lights were developed in the mid-1800s, the first LEDs weren’t created until the 1960s.
LEDs are a big deal because of how little electricity they use, and how long they last
The reason why the invention of the LED was such a big deal is because of two key factors:
- LEDs don’t burn out. They last a reallllllllly long time. LEDs can last for 20 or 30 years, which is why they have been used as indicator lights in electronics and machinery since the 1960s.
- They can produce a lot of light with very little electricity. An LED will produce the same amount of light as an incandescent bulb, while using around 10 to 15 percent as much energy.
LEDs are very efficient, even when compared to modern CFLs
While CFLs are very efficient, LEDs use about half as much electricity to produce the same amount of light. For example, compared to an old-style 60 watt incandescent light bulb, an equally bright CFL will use 13-15 watts, while an equivalent LED bulb will use 6-8 watts.
The rated lifespan of a CFL bulb doesn’t mean the same thing as the lifespan rating for an LED
Both CFLs and LEDs last a long time, compared to older bulbs. But LEDs blow CFLs out of the water. When you look at the packaging on light bulbs, CFLs will usually be rated for around 8,000 hours, while LEDs will be rated for anywhere for three to six times as long. But this doesn’t tell the whole story, because these two types of bulbs use different definitions for the word “lifespan.”
The lifespan rating for a CFL (as well as old incandescents) is pretty simple: it estimates how long you can use the bulb before it breaks and stops producing light. This is usually determined by taking a bunch of light bulbs and powering them until half of them burn out. The length of time it takes to achieve a 50% burn out rate is used as the lifespan rating for that particular bulb.
On the other hand, the lifespan of an LED tells you how long you can use it before the amount of light it produces drops by a certain percentage, compared to when it was brand new. This is called “lumen depreciation.” Studies of human beings have found that people generally don’t notice a different when light levels drop by as much as 30%. As a consequence, most LED manufacturers measure lifespan by seeing how long it takes for their bulbs to drop from 100% brightness (how bright they are when they’re brand new), to 70% of their original brightness. This lifespan measurement is sometimes referred to as “L70.” Some manufacturers use different figures, such as L80 (how long it takes for a bulb to drop to 80% of its original brightness), or even L90.
Why is the meaning of “lifespan” so different for LEDs, compared to other types of light bulbs? Well… that’s because well-built LEDs can last for just about forever. Even when you’re just talking about L70 lifespans, many bulbs have such high ratings that they can be used for 8 to 10 hours a day for 15 or even 20 years. At that point, the bulb may well last longer than the light fixture it’s installed in, so measuring how long it’ll take to die completely becomes essentially meaningless.
LEDs are less volatile than other light bulbs
Both incandescent and CFL bulbs contain mercury. This can present a serious problem in the case of breakage. It’s enough of a concern that in Canada, CFL bulbs aren’t supposed to be thrown in the trash, but instead should be taken to designated recycling centers. In comparison, while LEDs do contain extremely small amounts of toxic compounds such as lead and arsenic, they can be safely disposed of in the trash, and aren’t prone to breaking.