How Much Money Can You Save by Replacing Old Light Bulbs with Fluorescent Ones?

Compact fluorescent light bulbs will save you money.
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Cartoonists use lightbulbs to indicate a bright idea, but one of the brightest ideas you can have is replacing those old-school incandescent bulbs with new fluorescent ones. Forget those glaring, blinking, odd-shaped bulbs of old. New compact fluorescent lights, or CFLS, mimic the style and shape of traditional bulbs, so they’ll fit into almost any fixture and décor. Fluorescents will save you money, but how much money depends upon several factors.

Savings Components

Using CFLs saves you money in several ways. First, you’ll save by using less energy to light your home. Fluorescent bulbs also last longer, so you’ll save money by not having to replace light bulbs as often. Fluorescent bulbs are also cooler than incandescents, so you don’t heat up the room in the summer, which can mean lower cooling bills.

Energy Savings

Fluorescent bulbs use about 25 percent less electricity to provide the same light as comparable incandescent bulbs. When you shop for fluorescent bulbs, look for bulbs that say they are equivalent to 40-, 60- or 100-watt incandescent bulbs. You can also compare lumens, or the amount of light the bulb emits. For example, an 18-watt fluorescent bulb, provides 1,100 lumens, or about the same amount of lumens as a 75-watt incandescent bulb. Bulb wattage refers to the amount of electricity needed to keep the bulb on for an hour. In this case, the fluorescent bulb uses 57 fewer watts per hour than the incandescent bulb. If you leave the bulb on for 100 hours a month, you’ll use 57 fewer kilowatts. Check your electric bill for the amount you pay per kilowatt and multiply this by 57 to learn how much you’ll save per month by replacing one light bulb. Do this for all the bulbs you replace to arrive at your potential savings.

Replacement Savings

Your light bulb package should show an expected lifetime for the bulb. The typical 75-watt incandescent bulb lasts about 750 hours. The equivalent fluorescent bulb lasts 10,000 hours. So, in the time it takes the fluorescent bulb to burn out, you’d replace the incandescent bulb 13 times. If your incandescent bulb costs $1 and the fluorescent bulb costs about $9, you’ll still save $4 in replacement costs throughout the lifetime of the fluorescent bulb. Score a good sale or luck onto a free electric company giveaway and you’ll save even more.

Heating and Cooling

Other than in an Easy Bake oven, you probably don’t think of light bulbs as a source of heat, but they can contribute to the heat in a room. The difference may be negligible for a single lamp in a well-insulated room, but in a kitchen with 10 to a dozen ceiling lights, you can feel the difference. How much you’ll actually save depends on the outside temperature, where you set your thermostat and how many lights you’re using. But replacing hot incandescent with cool fluorescents can add to your summertime comfort.


You’ll save the most money by replacing your most-used lights with fluorescents. Lights in bathrooms, kitchens, offices and living room lamps are good places to start. Fluorescents are also a good idea in hard-to-reach lights, such as closet ceiling fixtures or basement lights, if only because you won’t need to replace them as often. Prices for fluorescent bulbs vary widely, with specialty bulbs costing more. But as fluorescent bulbs become more popular, the prices fall. Some electric companies give away standard fluorescent bulbs to encourage customers to make the switch. You can choose fluorescent bulbs that give off bright white or softer yellow light -- whichever you prefer.

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