While it might cost you a few more seconds, the most energy-efficient choice when you plan to be away from your computer is to completely shut down.

The amount of additional electricity used to start up a computer is negligible compared with the energy used to keep it running. And although you may hear that repeatedly powering-off and restarting a computer will affect its longevity, most computers will become obsolete far sooner than the effect of repeated daily shutdowns would kick in.

Now, because shutting down several times per day might not be most convenient or time-efficient choice, you can compromise by sticking to the following suggestions:

Shut down for long breaks. When you’ll be away from your computer for two hours or more, you should shut down completely. If that’s too hard, at least make an effort to shut down at night.

Use sleep mode. If you choose not to shut down, use the sleep mode function. You can set your computer to automatically power down if it becomes idle for more than 10 minutes.

Turn off the monitor. If you need to run applications while you’re away from your computer and, therefore, can’t shut down or use the sleep mode function, you can save significant energy by just turning off your monitor when you plan to be away from your desk for more than 15 minutes.

Avoid using screen savers. Screen savers do not save energy, and some actually consume more energy than not using one. Also, activating a screen saver will not allow the computer to enter sleep mode, which makes them the least energy-efficient of all choices for an idle computer.