Use a laptop instead of a desktop computer
Laptops are built not only for portability, but also for energy efficiency. Laptops need less electricity to run and spend more time in low power modes than desktops, making them about five times more efficient. Consider this when you buy a new computer and make a tech-savvy choice that's also energy smart.
Laptops readily revert into "sleep" mode in order to conserve battery life, which accounts for much of their energy savings. In addition, you are more likely to turn off or unplug a laptop, which further reduces its electric use.
Good to know: Laptops and desktops from many manufacturers are ENERGY STAR® certified. ENERGY STAR computers use 30-65% less energy than standard models by utilizing multiple low power modes. Best of all, you don't have to pay extra for the ENERGY STAR label, since efficient laptops and desktops cost the same as their conventional counterparts.