As we've demonstrated over the last few weeks, there are several alternatives to the old-fashioned incandescent light bulb, all of which will save on energy use and, ultimately, save you money. But we have yet to discuss the most popular alternative: Compact Fluorescent Light, or CFL, bulbs.

Apart from being the most widely available and affordable alternative bulb, there are a few other facts you should know about CFL bulbs before finalizing your lighting plan.

CFL Bulb Facts:

1, Although CFL bulbs cost a few dollars more up front than incandescents, CFLs use up to 75 percent less energy and last almost ten times as long as regular incandescents. Eventually, they pay for themselves.

2, Less fossil fuel is required to power a CFL bulb, which means fewer emissions are created in the process. According to the U.S. Government's Energy Star fact sheet, “If every home in America replaced just one incandescent light bulb with an ENERGY STAR qualified CFL, in one year it would save enough energy to light more than 3 million homes. That would prevent the release of greenhouse gas emissions equal to that of about 800,000 cars.”

3, Their brightness is measured in lumens instead of watts. However, most CFL packaging lists the equivalent wattage that would be required by a standard incandescent bulb to produce the same amount of light, making it easy for consumers to choose the right CFL to replace their old bulbs.

4, The color of light they produce is measured in Kelvins. The fewer the Kelvins, the warmer and yellower the light.

5, They also come in multiple shapes. You can find small, candle-shaped bulbs suitable for chandeliers and decorative lamps, globe-shaped bulbs that are perfect for vanity mirror lighting, and several other shapes in bet

6, Though they can take a moment to start, better quality CFL bulbs light quickly with no noticeable flicker. If the flicker bothers you, then it's a good idea to test a bulb in your home before investing in more of that particular brand and model.

7, They contain small amounts of mercury. Although this seems counter-intuitive to the claim that they're better for the environment, each bulb contains less mercury than is found in an old-fashioned thermometer, and it's only released into the air if a bulb is broken. To cut down on the risk, some states forbid disposing of burned-out or broken bulbs with your regular refuse and have special recycling and disposal programs available. Check with your local garbage collector to find out if any such restrictions or programs exist in your area. You can also check EnergyStar.gov for advice on how to properly dispose of a broken CFL bulb.

If these facts haven't convinced you to make the switch, then maybe this one will: many incandescent bulbs are gradually being phased out of production, and within the next three to five years will become illegal in Canada, Europe, Australia and the United States. So sooner or later, there won't be a choice. But why wait? The sooner you switch, the sooner the savings start adding up.