However, a little knowledge could save a considerable amount of money, since more than 16 percent of the electricity going into the average U.S. home goes toward lighting. Americans like their homes well-lighted. Here's a simple quiz on light bulb savvy. Two light bulbs with the same wattage always give off the same amount of light. Three bulbs with a total rating of 100 watts illuminate better than one 100-watt bulb.
Incandescent bulbs are cheaper to operate than fluorescent bulbs.
The answer to all four questions is false. They just go to the store, grab something, and slap it in. But wattage only measures how much electricity a bulb uses, not how much light the bulb emits. The true measure of light is called a lumen, and the lumen rating varies depending on the type of bulb. Typically, manufacturers print the wattage and lumens on the bulb or on its packaging, along with the number of hours the bulb can be expected to burn.