I discovered that I had 17 lightbulbs, some 60 watt, some 100 watt, on the first floor of my home. All were incandescent. With Opalco's help, I replaced all of them. It took less than 20 minutes. Opalco estimates that during just one evening, when most of those lights are on, my power use will go down from over about 4 kilowatt hours to less than one kilowatt hour. Over the course of a month, that is almost 100 kilowatthours, or about $9 every month. Since the bulbs last about 10 times longer than incandescents, I save money on the bulbs and the power. It adds up!