Energy Efficient Light Bulbs: Estimating Your ROI

Another win-win when it comes to lighting is a dimmer, which gives more flexibility and control, can enhance mood, and saves energy. Modern dimmers use simple electric circuitry to limit the amount of energy that is sent to a bulb. Most designs knock off 2-5% of the energy all the time they are installed, even if they are never turned down.

But let's say for argument that you have your lights dimmed to 50% as an average over the year. So for that fixture with the incandescent that you use six hours a day, you would be spending half as much for energy, or $8 a year instead of $16. And you will be doubling the life of your bulb, too. So you will go through one incandescent a year, instead of two.

Sound good? So how much does the dimmer cost? They can get quite fancy, with remote controls, LED displays and other bells and whistles. But standard wall dimmers can also be quite inexpensive. You can get a toggle-switch dimmer from Lutron, the biggest manufacturer, for $15 at Home Depot. The payback period for that would be less than two years, since you save $8.75 a year ($8 in energy plus 75 cents in light bulbs you didn't need).