Wednesday, August 15, 2007

21st Century Citizen’s Ultimate Guide to Compact Fluorescent Light (CFL) Bulbs

The new fad seems to be compact fluorescent light bulbs. Does switching to these bulbs actually save money? How much money will I save? Does this really make a difference to the environment? All of the answers are in the excellent article below.

The article below is from

21st Century Citizen’s Ultimate Guide to Compact Fluorescent Light (CFL) Bulbs

This is the first aricle in a series on Compact Fluorescent Light bulbs. We’re publishing this series so there will be a set of pages that provide everything a person needs to know about CFL lighting. If there is anything missing, please contact us so we can consider adding it to the series.

Introduction / Summary

Compact Fluorescent Light (CFL) Bulbs will save energy and cut your electric bills. They cost more initially, but will last as much as 10 to 15 times as long as regular light bulbs.

CFL bulbs only need 20-25% of the energy of a normal light bulb, so you’ll save money on electricity. How much money you’ll save depends on how high your bills are already. If your electric bill is $200/month then on average you could save $10-15/month by switching most of your lights to CFL bulbs.

One problem with CFL lights is that they are made using mercury, which is toxic. Newer CFL lights are now being made that use less mercury. Some US States are considering requiring the lights to be recycled.

Since they can do so much to lower electricity use, CFL lighting is expected to play a big part in slowing global warming and reducing oil dependency. In fact, according to the EPA’s EnergyStar program, we could save enough electricity to light 3 million homes if each home in America replaced only one light. That would prevent the same greenhouse gas emissions as taking 800,000 cars off the road.

Switching to CFL bulbs is a simple way to play a part in helping slow down global warning. You can save money and feel good while you’re doing it.


According to OSRAM’s on-line catalog, CFL lights can last between 6,000 and 15,000 hours of normal use. That’s over 10 times as long as the expected life of a normal light bulb which is only 700-1000 hours.

Cost and Payback

A normal 75 watt bulb priced at an on-line discount website cost 79 cents per bulb. A 6-pack of similar CFL bulbs was available from an on-line discount website for $15.16, or just about $2.50 apiece. Electricity costs are assumed to be about 10 cents per Kw-Hr.

Purchase cost per bulb:

  1. Normal Bulb = $0.79 USD (or 79 cents)
  2. Equivalent CFL = $2.50 USD

Electricity cost to use over life time:

  1. Normal Bulb: 75 Watts * 1000 Hrs * 10c/Kw-Hr / 1000 = $7.50
  2. Equivalent CFL: 20 watts * 12000 Hrs * 10c/Kw-Hr / 1000 = $24.00

Cost per year:

  1. Normal Bulb: $7.50 lifetime cost * 1.5 bulbs / year = $11.25 per year
  2. Equivalent CFL: $24.00 lifetime cost * 1/8 bulbs / year = $3.00 per year

In other words, a normal bulb costs $11.25 per year while the CFL costs only $3 per year. Switching to a CFL bulb will pay for itself in under 6 months.

Switching the top 10 lights in your home to CFL bulbs could save you $80/year on your electric bills.


The main drawbacks to using CFL Bulbs are that they cost more to buy initially, and they also contain small amounts of Mercury inside them.

The Mercury is used inside the bulbs to increase their efficiency. Only a small amount is used, but you should still be careful. (A CFL bulb contains only 1/100th of the mercury in old-style mercury thermometers.)

The main issues with Mercury are:

  1. If they break, the mercury can escape into your home, and
  2. They should not be disposed of into your normal trash.

If a CFL bulb breaks in your home, the amount of mercury released isn’t much — but you should use caution if this happens.

According to the U.S. EPA, here are directions to clean up a CFL bulb that has broken. [PDF] Here are their directions:

How should I clean up a broken fluorescent bulb?

EPA recommends the following clean-up and disposal guidelines:

1. Open a window and leave the room (restrict access) for at least 15 minutes.

2. Remove all materials you can without using a vacuum cleaner. Wear disposable rubber gloves, if available (do not use your bare hands). Carefully scoop up the fragments and powder with stiff paper or cardboard. Wipe the area clean with a damp paper towel or disposable wet wipe. Sticky tape (such as duct tape) can be used to pick up small pieces and powder.

3. Place all cleanup materials in a plastic bag and seal it. If your state permits you to put used or broken CFLs in the garbage, seal the CFL in two plastic bags and put into the outside trash (if no other disposal or recycling options are available). Wash your hands after disposing of the bag.

4. The first time you vacuum the area where the bulb was broken, remove the vacuum bag once done cleaning the area (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 or protected outdoor location for normal disposal.

Newer CFL bulbs are now being made that use about half of the mercury that older ones used.

Do Brands Matter?

In general, brands don’t matter that much. The main thing to look for is one that has low mercury content and is affordable.

Walmart recently put out a press release indicating they had pushed their suppliers into offering products that contained lower amounts of Mercury. The four manufacturers mentioned that were lowering their Mercury contents were GE Consumer & Industrial, Philips, OSRAM SYLVANIA, and Lights of America.

Where to buy CFL Bulbs

While it’s been accused of taking advantage of its size to dump problems on others, in this case I really can’t think of a better place to buy CFL lights than Walmart.

Walmart has taken the lead on CFL’s in terms of using their market power to lower the cost to consumers as well as in pushing the manufacturer’s to lower mercury content in the lights. In fact, on their website you can’t even find non-CFL lights.

On-Line References

The top references I’ve found on-line with regard to CFL Lights are:

  1. Wikipedia’s Entry on Compact Fluorescent Lights
  2. Walmart for price comparison and shopping
  3. Popular Mechanics Article, May 2007
  4. NPR Story on CFL’s, Feb 15, 2007

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