" If every American home replaced just one light bulb with a light bulb that's earned the ENERGY STAR, we would save enough energy to light 3 million homes for a year, save about $600 million in annual energy costs, and prevent 9 billion pounds of greenhouse gas emissions per year, equivalent to those from about 800,000 cars."
Incredible impact! So, how does this directly effect YOU? CFL bulbs last longer, up to 10x longer than your standard incandescent bulb. They also give off significantly less heat (75% less!), so your house will be cooler, you'd be amazed out much the standard bulb heats up your house! Yes, CFL bulbs tend to be more expensive than your standard incandescent bulb. BUT, there are ways to decrease that cost some. Your local power company may be willing to help you out. Salt River Project, my power company, has a program in place to offer discounts on CFL bulbs at the local hardware store. Also, while this offer has ended with SRP, check your power company to see if they have something like this going on, SRP was offering, FOR FREE, a 6 pack variety pack of CFL bulbs. I have found CFLs in multi-packs at Costco in the past for a really good price. SRP also has a handy-dandy calculator so you can see how much CFLs will end up saving you, you might be surprised!There are a few things to be aware of if you go CFL. One, very important detail, they contain a small amount of mercury. So, this means, do NOT just chuck them in the trash in 4 years when they burn out (no joke, we just had some burn out that we put in when we moved in our house 4 years ago), you should recycle them, Lowe's, Home Depot, Ace, etc should have recycling centers for this type of thing. If not, use earth911 to find a recycling center near you. The other one is that they don't look like your incandescent bulb and you may have to find the equivalent wattage for your lamp. Also, generally they do not work well in dimmers, there may now be special CFLs on the market for this purpose, but there were not when we were looking last. Also, for similar reasons, they do not work well with timers, so if you want to swap out your outdoor lights for CFLs and use a timer, be aware of this.
So there are pros and cons, but I think the pros outweigh the cons substantially! Give them a try, replace the next bulb that burns out with a CFL and see what you think!