Q: I am 11 years old and I would like to know why compact fluorescent light bulbs use less electricity than regular, old-fashioned incandescent light bulbs. I asked my father and he said that he is clueless and that I should ask Rachael. What is the answer?
A: I'm glad you asked. Only about 10 percent of the electricity you supply to an incandescent bulb becomes light. The rest is lost as heat, which is why incandescent bulbs get so much hotter than compact fluorescent bulbs (CFLs).
However, a CFL can convert 25 to 30 percent of the electricity you supply it into light. Because incandescent bulbs lose so much energy, they need a lot more of it than a CFL does to deliver the same amount of light. For example, to get the same amount of light as a 100-watt incandescent bulb, you only need a 27-watt CFL.
If you're interested in learning more about energy, your teacher can arrange to have an expert come to your class from the Vermont Energy Education Program. Their website is
. Thanks for writing!