When technological improvements make their way into an industry, things move fast. It wasn't long ago that needing to replace a light bulb only required a trip to the local store, choosing an incandescent bulb with the proper wattage, heading home, and making the switch. Recently, technology has changed the lighting industry by providing options to consumers that weren't available just a few short years ago. Now, that simple trip to the local store can result in a lot of head scratching and questions. In this article we'll examine the difference between incandescent, CFL, and LED bulbs to help you determine which one is right for your lighting needs.
So many bulbs, so many choices
With so many options, it's easy to get overwhelmed when selecting the right light bulb for your home. There are three main types of bulbs available to consumers today, although some types of incandescent bulbs are being phased out by manufacturers in favor of more energy efficient bulbs.
Incandescent light bulbs are the one we (most of us, anyway) grew up with. It's an electric light with a wire filament heated to a high temperature, by passing an electric current through it until it glows with a visible light. The hot filament is protected from oxidation with a glass bulb that is filled with inert gas. The incandescent bulb has been the norm in household and commercial lighting, as well as portable lighting such as car headlamps and flashlights, for decades. The inefficiencies with incandescent bulbs (they convert less than 5% of the energy they use into visible light) made it a perfect product for technological innovation to bring consumers something more efficient and environmentally friendly.
Compact fluorescent light
An energy shortage - the 1973 oil crisis - forced lighting engineers to develop fluorescent bulbs that could be used in residential situations. In 1974, researchers at Sylvania began investigating how they could manipulate existing fluorescent lights to make them smaller, produce them in larger quantities, and make them feasible for household use. It wasn't until 1976, when General Electric figured out how to bend the fluorescent bulb into a spiral shape, and thus created the first compact fluorescent light, or CFL. CFLs came to market in the mid 1980s and carried hefty price tags of $25-$35 per bulb. They were often too bulky to fit into many household fixtures and had low light output compared to incandescent bulbs. The bulbs continued to be improved in terms of performance, and today a CFL bulb is a viable and affordable incandescent alternative for residential and commercial use. CFLs use approximately 75% less energy than incandescent bulbs and last approximately 10 times longer. Improvements in manufacturing efficiency and increased consumer demand has driven the price down to an average of between $1-$2 per bulb.
While the term "LED," or light-emitting diode, may be a part of everyone's vocabulary these days, it wasn't until recently that LEDs started to be used in common household applications. LEDs use a semiconductor to convert electricity into light, do not take up a lot of space, and can emit light in a specific directions.
Nick Holonyak Jr., invented the first visible-spectrum LED in the form of red diodes. Pale yellow and green diodes followed next, and the combination of green, yellow, and red made these LED lights perfect for practical applications such as indicator lights. The invention of the blue diode in the 1990s eventually led to the discovery of white LEDs by coating the blue LED with a phosphor to make it appear white. These continued breakthroughs led manufacturers to use LEDs in a variety of common applications such as televisions, traffic signals, flashlights, and more.
Which one is right for me?
After making your trip to the store, standing in front of the massive selection of bulbs, and scratching your head a bit, it's time to make a decision. If you have been thinking about upgrading your outdated incandescent lights, this trip to the store can be both confusing and overwhelming. Below, we break down the various factors of making a lighting choice to help you be the most educated consumer you can be when it comes to selecting the proper lighting for your home or business.
Light bulb efficiency is measured in what is called luminous efficacy, or how well a light source produces visible light. A light bulb's efficiency is a measure of emitted light (lumens) divided by power it draws (watts). A bulb that is 100% efficient at converting the energy it uses into light would have an efficacy of 683 lumens per watt, or lm/W. A typical 60-watt incandescent bulb has an efficacy of 15 lm/W, an equivalent CFL bulb has an efficacy of 73 lm/W, and an equivalent LED bulb has an efficacy between 90-140 lm/W.
Standing in front of your many options, it's temping to reach for the bulb or bulbs with the lowest initial cost. Light bulbs are the purchase that keeps on taking, and will continue to cost you money month after month in the form of your utility bill. When making a lighting decision, it's important to consider both the upfront cost and the total cost of ownership (TCO). The average upfront costs for all three types of bulbs is as follows:
- Incandescent - $0.94
- CFL - $1.60
- LED - $4.99
At first glance, incandescent bulbs are attractive because of their low initial cost. If you're replacing a lot of bulbs all at once, the initial investment in LEDs can seem costly as opposed to incandescents and CFLs. However, if you look at the long-term cost of purchasing and operating the three different types of bulbs, you'll see quite a price difference. The below numbers factor in the average cost from above, average lifespan, utility rates, and average use.
- Incandescent - $236.07
- CFL - $52.31
- LED - $31.43
The average lifespan of a light bulb is measured in the average hours a bulb will last while in operation. Incandescent bulbs continued to make improvements to their efficiency and lifespan over the years, but have not been able to come close to the average lifespan of either CFL or LED bulbs.
- Incandescent - 1,200 hours
- CFL - 8,000 hours
- LED - 50,000 hours
We live in a world where consumers and businesses are increasingly environmentally conscience. The lighting in our house may not be a common area where we look to improve our environmental friendliness, but the difference between incandescent, CFL, and LED bulbs can have a significant impact on the environment.
Both incandescent and LED bulbs do not contain a mercury, a potentially toxic substance to both you and the environment. CFL bulbs do contain mercury, albeit a very small amount. According to the Environmental Protection Agency, CFLs contain an average of four milligrams of mercury sealed within their glass tubing. For perspective, older thermometers contain about 500 milligrams of mercury, or an equal amount to over 100 CFL bulbs. While this small amount of mercury is not harmful to you contained within the bulb, it is important to properly dispose of CFL bulbs which break or reach their end of life. Purchasing CFL bulbs may actually reduce the amount of mercury in the environment. Mercury is found naturally in many rocks including coal. When coal is burned at a power plant to produce electricity, mercury is released into the environment. Purchasing CFL bulbs increases the energy efficiency of your home, resulting in less coal needing to be burned, and thus, less mercury being released into the environment.
Another important aspect to consider with lighting as it pertains to the environment is the Carbon Dioxide emissions of light bulbs. Using an average household amount of 30 bulbs, the amount of total carbon dioxide emitted by each type of bulbs is below:
- Incandescent - 1,051 pounds per year
- CFL - 4,500 pounds per year
- LED - 451 pounds per year
The future of light
Between 2012 and 2020, the United States is moving forward with phasing out incandescent bulbs. While the new regulations do not require consumers to replace old incandescent bulbs, there is a chance that these bulbs will not be available to purchase once they reach their end of life. In 2012, 100-watt incandescent bulbs were phased out, in 2013 75-watt incandescent bulbs were phased out, and in 2014 40-watt and 60-watt incandescent bulbs were phased out. By 2020, a second tier of restrictions will become effective, which will require all general-purpose bulbs to produce at least 45 lumens per watt, a similar output to current CFLs. Certain exemptions to the phase out of incandescent bulbs exist for specialty lights, appliance lamps, stage lighting, plant lights, candelabra lights and more.
With the phase out of incandescent bulbs, it leaves consumers with more limited, albeit better, options when replacing bulbs. While CFL bulbs come with many benefits, there are certain drawbacks to consider. For example, CFL bulbs are often very sensitive to temperatures and humidity, and can also have their lifespan reduced drastically if placed in a room where the light cycles on and off frequently, such as a closet.
LED bulbs have no sensitivity to low temperatures or humidity, turn on and illuminate a room instantly, are extremely durable (for a light bulb), and their lifespan is not effected by on and off cycling.
Ultimately, selecting the right bulb for your home is your decision. The increased consumer demand for LEDs, and the constantly improving technology behind them, should continue to drive the price of bulbs down below their current $5 per bulb average. Already, new advances in LED bulbs have allowed them to mimic the soft white or yellow glow of old incandescent bulbs, allowing consumers to choose the "flavor" of light that is perfect for their room and personality.