✔ When you leave a room for a short while, is it economical to turn out the lights? Yes—if your source of light is incandescent bulbs. You save money by turning off regular light bulbs whenever you leave a room, even briefly. But if you have fluorescent lighting, it is generally best not to turn it off if you will be gone only a short while. Fluorescents cost more initially but they use less electricity than incandescent bulbs; switching fluorescents on and off shortens their life-span.