Use less power and improve battery life
Computers can use a lot of power. By using some simple energy-saving strategies, you can reduce your energy bill and help the environment. If you have a laptop, this will also help to increase the amount of time it can run on battery power.
when you are not using it. This significantly reduces the amount of power it uses, and it can be woken up very quickly.
Turn off the computer when you will not be using it for longer periods. Some people worry that turning off a computer regularly may cause it to wear out faster, but this isn't the case.
Use the Power preferences in System Settings to change your power settings. There are a number of options that will help to save power: you can the display after a certain time; (for laptops); and have the computer if you have not used it for a certain period of time.
Turn off any external devices (like printers and scanners) when you're not using them.
Laptops, netbooks, and other devices with batteries
; powering the screen accounts for a significant fraction of a laptop's power consumption.
Most laptops have buttons on the keyboard (or a keyboard shortcut) that you can use to reduce the brightness.
If you don't need an Internet connection for a little while, turn off the wireless/Bluetooth card. These devices work by broadcasting radio waves, which takes quite a bit of power.
Some computers have a physical switch that can be used to turn it off, whereas others have a keyboard shortcut that you can use instead. You can turn it on again when you need it.
More advanced tips
Reduce the number of tasks that are running in the background. Computers use more power when they have more work to do.
Most of your running applications do very little when you are not actively using them. However, applications that frequently grab data from the internet, play music or movies can impact your power consumption.