A fluorescent bulb uses 1/5 to 1/3 as much electricity as an incandescent bulb with comparable lumen ratings and last up to 20 times longer. It can generate between 50 and 100 lumens per watt, making it four to six times more efficient than incandescent bulbs. You can buy a 15-watt fluorescent bulb that produces the same amount of light as a 60-watt incandescent bulb. Fluorescents produce less heat and are much more efficient. Available in a wide spectrum of colors; warm white tones best duplicate the color of incandescent.