It’s Official: You Can Stop Turning off Lights When Leaving a Room

Your parents probably told you to turn off the lights every time you leave a room. And they were right — until now.

Modern bulbs use so little energy that the amount you save by flipping off the light switch is essentially “meaningless,” according to a report from The New York Times’ Wirecutter team.

In the past, many of us used incandescent bulbs that were energy hogs. These bulbs released more energy in the form of heat than light. In fact, 90% of the energy was given off as heat, according to the U.S. Department of Energy.

But today’s compact fluorescent (CFL) and particularly light-emitting diode (LED) lighting is much more energy-efficient. That is why Wirecutter says you really don’t have to worry about turning off the lights when you leave a room. In the report, Wirecutter smart-home editor Jon Chase says:

“While the principle of not wasting may be noble, the energy used is so minuscule as to be meaningless.”

The Department of Energy doesn’t exactly recommend leaving lights burning perpetually.

For CFLs, the Department of Energy offers the following advice: If you plan to leave the room for 15 minutes or less, keep the lights on. Otherwise, turn them off. Switching these lights on and off frequently shortens the life of the bulb. So, the length of time between visits to the room dictates whether to turn off the lights.

On the other hand, switching LED lighting on and off will have no impact on its lifespan. So, the Department of Energy effectively agrees with Wirecutter when it comes to LED bulbs.

So, thanks to the energy efficiency of today’s bulbs, particularly LED ones, there is little need to worry about leaving lights burning. Chase says you could leave a dozen LED bulbs switched on “24/7, and they would still consume less energy than what a typical fridge uses in a day.”