Changing light bulbs is the simplest, most cost-effective means of reducing our home energy use. The electricity we use for lighting results in carbon emissions equal to 70% of those from all automobiles. Traditional incandescent bulbs are notoriously inefficient: they waste 90% of their energy consumption in generating heat rather than light, making the bulbs extremely hot to touch and unsafe.
CFL (compact fluorescent light) bulbs have been in the news a lot lately. California, Connecticut, North Carolina, and Rhode Island, are all in the process of enacting legislation to ban incandescent bulbs. Canada, Australia, and several European countries are phasing out incandescents over the next few years. Beijing's municipal government is subsidizing 90% of the price of CFL bulbs in an effort to improve the city’s dismal air quality.
Many people are reluctant to do a mass change-out of bulbs because CFL bulbs cost significantly more than their incandescent counterparts. However, CFL bulbs are much cheaper in the long run. For example, assume the following:
- a typical CFL bulb costs $5, lasts 10,000 hours
- a comparable incandescent bulb costs $0.75, but lasts only 1000 hours and uses 3 to 4 times more energy
- the average cost of electricity in South Carolina is approximately $.09/kw
Over a period of 10,000 hours (417 days) of bulb use, the cost of bulbs would be $5 for the single CFL bulb and $7.50 for the ten incandescent bulbs, yielding a savings of $2.50 for the bulbs alone. The electricity cost for the incandescent bulbs would be $90, vs about $25 for the CFL bulb, providing additional savings of $65. So by replacing a single light bulb, we save $67.50 over the life of that bulb. When we replace more bulbs, our savings multiply. Finally, don't forget the heat. Since incandescent bulbs waste most of their energy generating heat, home cooling costs in the summer increase in order to offset the heat generated by inefficient light bulbs.
By replacing incandescent light bulbs with CFL bulbs, we consume less electricity meaning less coal-based power will have to be generated to meet our demand meaning less greenhouse gases will be released into the atmosphere. All while saving us money at the same time!
CFL technology has improved greatly over the last few years. CFL bulbs once provided an unflattering blueish glimmer. But the newer generation of CFL bulbs provide a warm, flicker-free light that is generally undistinguishable than the light we are accustomed to. Look for CFL bulbs with a color rating of 2700K, which is similar to incandescents. While CFL bulbs were once only available in the spiral form, there are now many models to fit nearly all household uses: traditional “bulb-shaped” globes, dimmable bulbs, 3-way bulbs, and floodlights. Like incandescents, they come in various wattages (though with a different scale – a 25 watt CFL bulb provides the same light as a 100 watt incandescent bulb).
There are even full spectrum CFL bulbs which produce light with the same characteristics as sunlight (with a color rating of 5000K). Colors appear richer and truer under full spectrum light. Because it mimics the sun, full spectrum light can improve visual clarity, mood, productivity, mental awareness, and sleep cycles. You’ll notice less eye strain when reading with this light. Because of their similarities to sunlight, these light bulbs are appreciated by houseplants as well.
One downside of CFL bulbs is that they contain trace amounts of mercury, a toxic pollutant. The National Electrical Manufacturer Association enacted standards effective in 2007 that restrict the amount of mercury present in CFLs to five to six milligrams, depending on wattage (that amount that would fit on the tip of a ball point pen). Many lighting manufacturers are working to eliminate, or at least, greatly reduce the amount of mercury in their bulbs, but cost-effective mercury-free CFL lighting is still probably 5 or so years away.
Ironically, fluorescent bulbs cause far less mercury contamination than incandescent bulbs, though incandescents contain no mercury. The highest source of mercury in our air and water comes from the burning of fossil fuels, such as coal, for electricity. Since fluorescent bulbs use 67-75% less energy than an incandescent bulb and last up to ten times longer, they result in far less mercury pollution in the long run. Stated another way, a coal-burning power plant emits 3 to 4 times more mercury to produce electricity for an incandescent bulb than for a CFL bulb.
However, the mercury in the CFL bulbs is cause for concern when we use them in our homes. As long as fluorescent bulbs remain intact and are disposed of properly, the mercury in the bulbs poses no threat to humans or the environment. Keep in mind that the amount of mercury in a CFL bulb is about one-fifth of that found in watch batteries and 100s of times less than other common items (thermometers, thermostats, electrical switches, etc.) The EPA strongly recommends recycling fluorescent bulbs (DwellSmart and IKEA provide an in-store drop-off) rather than putting them in the garbage.
If a fluorescent bulb breaks, the EPA recommends that you do the following:
- Open a window and leave the room for at least 15 minutes.
- Remove all materials you can without using a vacuum cleaner. Wear disposable gloves, if available (don’t use bare hands). Carefully scoop up fragments and powder with stiff paper or cardboard. Wipe the area clean with a damp paper towel or sticky tape (such as duct tape).
- Place cleanup materials in a plastic bag and seal in another plastic bag. Put into the outside trash. Wash your hands.
- The first time you vacuum the area, remove the vacuum bag after cleaning (or empty and wipe the canister) and put the bag and/or vacuum debris, as well as the cleaning materials, in two sealed plastic bags in the outdoor trash.
For more information on mercury, see the EPA’s website.
Given all the facts, CFL bulbs definitely provide for a brighter future than sticking with incandescents. But we’re even more excited about LED technology for lighting.
While a typical incandescent bulb emits around 15 lumens of light per watt of electricity and a CFL generates about 67 lumens per watt, an LED bulbcan produce 300 lumens per watt. To put it another way, you could replace a 100-watt incandescent bulb with an LED bulb that used a miserly 6 watts. The key challenges for getting LED bulbs to the mass market are primarily their cost and their color quality. Most LED bulbs emit a "cool", bluish light (sometimes called "lunar white") that most people find unappealing in the home. Now researchers have applied a layer of nanocrystals that absorb some of the LED's blue output and emit their own red and green light. The result is that the LED bulb produces a soft, warm light.
In addition to their greater efficiency, LED bulbs offer other advantages over CFL bulbs – they have an even longer lifespan and are free of mercury. The one remaining hurdle is their much higher cost. As the technology improves and production increases, their cost will surely come down. So, in the meantime, keep switching out incandescents for CFL bulbs, but keep an eye out for the next generation LED bulbs!
DwellSmart carries a large selection of energy-efficient CFL bulbs.