Turning lights off as you leave the room can save energy and money.
Most lights should be turned off when they’re not needed. Incandescent lights should be turned off whenever they aren’t needed because they are the least efficient type of lighting, with 90% of the energy being given off as heat and only 10% light.
Halogens bulbs are more efficient than incandescent lights but should still be turned off as they use the same technology.
CFL lighting is very efficient, it is generally accepted that if you will be leaving the room for more than 15 minutes or less then it should be left on, if its any longer then it should be turned off. The operating life of a CFL bulb is effected by the number of times its switched on and off.
Could you save energy and money by turning lights off when you leave the room more often?