How many light bulbs are in your home?

Have you ever wondered just how many light bulbs you have in your home? Have you ever counted? Not counting the bulbs in our refrigerator, we have 104 light bulbs on the first floor of our house alone. So why am I counting light bulbs? Am counting light bulbs because beginning in 2012, the all too familiar incandescent light bulb will, for the most part, be a thing of the past.

The Energy Independence and Security Act of 2007, also known as the Clean Energy Act of 2007, requires roughly 25% greater efficiency for light bulbs phased in from 2012 to 2014. Because incandescent bulbs are so inefficient (they are really miniature heaters that emit light as a byproduct), the Clean Energy Act will outlaw the sale of these bulbs, with a few exceptions. And by 2020, the Act requires roughly 200% efficiency for most bulbs.

So what will replace the incandescent bulb? The answer is two-fold: compact florescent bulbs (CFL bulbs) and LED bulbs. Today, both have significant advantages and disadvantages over incandescent bulbs. In the long run, however, most experts believe that the LED bulb is our light source of the future. Here is some basic information about each type of bulb, followed by a strategy to replace your incandescent bulbs between now and 2012.

CFL Bulbs

Fluorescent bulbs were developed about 70 years ago. Inside a CFL bulb, an electric arc energizes mercury atoms, causing them to emit ultraviolet rays. A coating on the bulb’s interior surface converts UV rays to visible light.

Average Lifespan: 6,000 hours

Average Cost: $7

Energy Consumption: About 75% less than an incandescent bulb

Advantages: The big advantages here are that CFL bulbs use a lot less energy than incandescent bulbs and the cost of the bulb on a per hour basis is less.

Disadvantages: The CFL bulb contains trace amounts of mercury. While manufacturers are working to reduce the amount of mercury in a CFL bulb, clean up of a broken CFL requires special care. The light emitted by CFLs also takes getting use to.

LED Bulbs

An LED light uses semiconductor chips treated to release light when charged with electricity. Manufacturers have produced an assortment of colors and are striving to perfect white LEDs. LEDs are now used in brake lights, traffic signals, Christmas lights and recessed lights. Experts think LEDs eventually will replace CFLs.

Average Lifespan: 50,000 hours

Average Cost: $40

Energy Consumption: A 6-watt bulb produces as much light as a 40-watt incandescent, while producing little heat.

Advantages: LED bulbs last up to 10 times longer than CFLs and use anywhere from 1/3rd to 1/30th the electricity of a standard incandescent light bulb.

Disadvantages: LED bulbs are expensive, although the costs are recouped over the life of the bulb. Also, the industry has yet to produce a white LED bulb that effectively disperses the light. As a result, LED bulbs today are best used for recessed/track lighting or spotlights.

Incandescent Bulbs

An incandescent bulb contains a tungsten filament that glows white-hot when electrified. In their basic form, incandescent lights have been manufactured for more than a century.

Average Lifespan

: 1,000 hours

Average Cost: $2

Energy Consumption: These bulbs convert nearly all electricity to heat. Advantages: The bulbs are inexpensive, although their per hour cost is higher than CFL or LED bulbs.

Disadvantages: The typical incandescent bulb burns for just 1,000 hours and consumes substantial energy.

Incandescent vs. CFL vs. LED: Which one to buy

Our plan is to replace incandescent light bulbs as they burn out with CFL or LED bulbs. With this approach, we get full use of the existing bulbs, and can spread out the replacement costs of the new bulbs over a year or two. By 2012, we should have replaced most if not all of the light bulbs in our house.

For recessed lights, we plan to use the LED bulbs. They are perfect for this type of lighting, are the most energy efficient, and last far longer than even a CFL bulb. The absence of mercury in an LED bulb is also a big plus.

With one exception, we plan to replace the remaining lights with CFL bulbs. Although the mercury content is a concern, the amount of mercury in each bulb is becoming less and less as manufacturers improve the technology. Today you can buy what are called “Alto” CFLs that have less mercury than other CFL bulbs. Philips is one manufacturer of these reduced mercury content bulbs.

The one exception would be any bulb that has a high risk of breaking. The best example here would be a floor lamp in my son’s bedroom. We’ll stick with an incandescent bulb and hope the technology improves by 2012 for alternative light sources.

How much do CFL bulbs really save?

So how much would changing out incandescent bulbs actually save? Well, according to an estimate by General Electric, factoring in replacement costs of incandescent bulbs and the energy costs, over the lifespan of a single CFL bulb, total savings amount to about $35. Given the lifespan of a CFL bulb, this savings likely spans two to four years, depending on the usage of the bulb. Multiply that savings by the number of actively used light bulbs in your home, and the money saved is likely very significant.

If you are interested in CFL bulbs, Amazon has a very good CFL Bulb Buying Guide.

Topics: Smart Money

9 Responses to “How many light bulbs are in your home?”

  1. It is great to see information that helps the planet. I have heard that if everyone in the US replaced thier light bulbs with CFL or LED we could close down ALL the coal burning plants in the country. WOW. I really do not like the color of CFL nor the price of LEDs, though I did find a several price effective web sites for LEDs. One, has some bulbs for much less than the $40 stated here. I actually got a bulb with a remote control and it displays 15 colors and dims for less than $32. Cool for parties in my dorm. There is a wake up call that this planet needs to hear to become more sustainable, and if it takes a Law to wake up our citizens then so be it.

  2. Led Master

    Sam’s Club now sells LEDs.
    2 40 watt Par type bulbs for about $15 so that is less than $8 per bulb.
    The price is dropping and LEDs don’t have the dangerous and poisonous
    mercury that CFLs do.
    They also sell LED night lights, and other LEDs for outside lights.
    At this current price they pay for themselves in about 1 year or less. They
    are rated at 30,000 hours.

  3. I have been following the “replace incandescents with CFL’s when they go out” strategy for a while now, and so far so good. However, I find that CFL’s designed to replace flood lights in recessed lighting situations just don’t cut it. Too slow to warm up.

  4. I recently replaced all of the bulbs in my entire house with CFLs. We have exposed bulbs in the bathrooms and the swirly CFLs just didn’t look right, so we got the CFLs with the glass covering that looks like a traditional bulb. For some reason, those bulbs take a bit to warm up and are pretty dim when first turned on. We’ve actually found that to our advantage in the bathrooms. In the mornings and in the middle of the night if someone needs to go to the bathroom, when they flip the switch, they aren’t bombarded with light from the three bulbs right away. It’s fairly dim and slowly gets brighter. It’s a nice transition when coming in from the dark. Of course, it’s a disadvantage when you need that light to pull a splinter in the middle of the day. You have to wait for the lights to warm up before getting the necessary light.

  5. I can’t share any details yet, but there is a new LED being produced (under the auspicious hold of NINE patents) that not only produces a true white light that can be dispersed in any angle, it also puts off NO heat and can be programmed to produce any strength from 100 to 10,000 lumens. As a nifty little added bonus, it will email you when it needs changing. But don’t expect a lot of emails, this one lasts 100,000 hours – that’s about 20 years if you use it 12 hours a day every day. Intrigued? Send me an email and I’ll make sure you get the details when it’s available to the public – which is technically now if you’re a wholesaler or buying for a commercial project.

  6. Green Consumer

    I am a big fan of LED lighting. Choose a bulb that fits the application (lumens and color) and you will be happy. Unfortunatly many manufacturers and vendors overstate (I’m being kind here) their products specifications.

    I have purchased 45 LED bulbs and have had mixed reliability.
    The good news – some are very reliable. I have five LED bulbs outside that have run dusk to dawn for two years with no problems.
    The bad news – some bulbs are VERY unreliable. VERY high failure rates.
    I purchased 12 LED bulbs and 7 have failed (8.5W product 47856 from To make matters worse they are refusing to replace them now.
    Beware of This company is selling products that they know are defective. No support for failed LED bulbs. These bulbs are very expensive ($20 – $105) and in some cases last only two or three weeks. They refuse to replace defective bulbs. is selling known defective products and has bad customer service.

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