LED lights have been used as indicators on the front panels of our home electronics for over 30 years. Now, recent improvements in technology have allowed Light Emitting Device technology to become the main lighting choice for our household lighting. Legislation now mandates the use of more efficient lighting in many countries causing CFL bulb use to become widespread. This has created a keen interest in other light technologies by the public. However, as a consumer, it is easy to get bogged down in technical details when trying to pick out your first LED light bulb. Various aspects of each lighting technology are considered below, along with the pros and cons of each.
The sticker shock won’t wear off in an hour or two or even a week. LED bulbs are really expensive. When CFL bulbs first came out, they were $10 apiece and incandescent bulbs were $0.50. Yet, people bought the CFL type, anyway. However, after years of sales growth and economies of large scale manufacturing, CFL bulbs can now be found on sale for $1. Right now, LED bulbs that have luminance output equal to 40-60W incandescents, are $24-60 apiece. Considering how far the price of CFL bulbs has fallen since their inception, it’s reasonable to expect LED light bulbs to be $5-10 apiece in the next few years.
Lifespan and Dimmer Use:
Standard inexpensive incandescent bulbs have a lifespan of 750-1000 hours. You can buy 5000 hour bulbs that are designed for 130V and simply run cooler at 120V, to increase their lifespan. Those bulbs take a big efficiency hit, since they have only 63% of the light output at 120V. You end up buying the 100W version to get back to that magical 800 lumens output level, thus raising your utility bill. Using a dimmer control to lower your lights creates a very inefficient use of the incandescent bulb, also. The original 3-way bulb with two switched filaments was actually the correct way to create multiple lighting levels.
CFL bulbs average 10,000 hours of life and the newest LED lights are 50,000 hours lifespan. The lifespan for an LED is based on when it reaches 70% light output, not when it quits working. Incandescent bulbs generally fail catastrophically, from filament fatigue. When CFL bulbs begin to fail, they grow dimmer and flicker a lot. LEDS just gradually get dimmer so could be useful far beyond the 50,000 hours, depending on how long the electronic power supply inside the bulb lasts. Inherently, both CFL and LED lights don’t work on dimmers, unless you buy special versions.
Standard incandescent and CFL bulbs are made of fragile glass. Both are likely to break sometime during the disposal process, if not when you are trying to cram more garbage into the trash container, then definitely when the garbage truck compacts his load. Fortunately, there are no hazardous materials in the incandescent models other than glass shards. CFL bulbs contain mercury and need to be carefully disposed of, just like batteries. Each year, the waste from failed fluorescent light products creates 50,000 pounds of toxic mercury. If you break a bulb in your home, you run the risk of inhaling mercury vapors. For proper disposal, take them to a recycle center or to Home Depot. LEDs, by design, are enclosed in rugged epoxy, and have only trace compounds of gallium arsenide inside. They are not considered hazardous.
Electric bills are costly and energy prices just keep going up. A 60W incandescent bulb is equivalent to a 14 watt CFL bulb or a 9.8W LED bulb. You use 43% more energy with a CFL bulb than with an LED bulb. Accounting for the five times longer life and the energy savings, a $14 LED bulb would wash out with a $2 CFL bulb, in terms of lifetime running cost. Right now, a $25 LED bulb would have about half the lifetime running cost of a 60W incandescent bulb, making it a good upgrade path from old style bulbs.
Incandescent bulbs can work at almost any ambient temperature. In fact, they are the only lighting method that could stand the temperature in a home oven. The failure mode on incandescent designs is from filament fatigue. Every time the light is turned on or off, that filament expands or contracts. Extreme temperature and humidity increases this fatigue, greatly shortening the life. For instance, using a standard bulb in a refrigerator or for outdoor use will lower the lifespan to a few hundred hours, in my experience.
CFL bulbs operate from 5-105 degrees F. This makes them marginally usable in a hot shed in the summer or in cold climates for carport lights. Traffic signal lights went straight from special long life incandescent lamps to LED lamp models, bypassing CFL technology, entirely. For home use, more expensive CFL models have been designed to be used outdoors or in appliances, but they cost $10-15 each. At that price, the LED light wins for a cheaper lifetime operating cost.
LED light bulbs are good from -22F to 176F, making them universally usable, except in ovens. Many of the better LED models operate from 85-260VAC, which means that brownouts will not dim them nor will modest power line surges during thunderstorm blow them out. Special models are available that work on dimmers.
Sizes vary greatly with average diameters of three inches and lengths from 4-6.3 inches. Why are they so big, you ask? LED junctions are very compact and around 90% efficient in producing light, which means that a 10W LED still generates a watt of heat. That’s why they add the aluminum body on it for heatsinking. The intent is to keep that lifespan high at 50,000 hours. You will have to check your fixtures to see which can hold the larger LED bulbs. CFL bulbs have similar issues with sizes. Many are long and skinny or have fat bases and won’t work in all table lamp or ceiling fixture designs.
The LED lighting industry needs early adopters to drive those prices down for the masses. CFL prices have flattened out at $1-2 apiece, so the LED industry will need to drop their prices by at least half to really get competitive. Consider changing just one bulb in your house to an LED type, such as the main lamp in the living room or kitchen. Pick the location that gets the most use. Other home products using LED technology, that are already competitive, are in small reading lamps and flashlights. LED desk lamps, for local lighting around keyboards, are a great way to cool off that home office in the summer months and do your part for energy conservation.