Although modern monitors are very efficient, having something producing a wall of light constantly can use a fair amount of energy over time, this is multiplied if you use multiple monitors or have your computer connected to a TV.

The first thing you can do to save power is turn off your monitors. Depending on where you live and the internet speed you have, one night might be enough to download even the biggest games. But there are some ways to limit the amount of power use the computer if you need to leave it on overnight.

The main reason that most people will not want to leave their computer on overnight is the energy cost, especially if they are using a powerful gaming computer that eats power.