Fluorescent light!

 This a picture of a single fluorescent light bulb. Notice how bright it is shining considering it is only thirteen watts. Compared to incandescent bulbs, which converts much of its energy to heat, the fluorescent lamps barely use any energy converted into heat. Therefore, a 100-W incandescent light bulb shares the same brightness as a 13-W fluorescent light bulb. The fluorescent lightbulb uses gases such as argon and mercury to cause a reaction inside the lightbulb to cause UV rays which is used a form of light.