Modern computers don't use a fixed amount of power. Just listen to the fans spin up to blow away heat when your laptop or desktop is running a compute-intensive

Modern computers don't use a fixed amount of power. Just listen to the fans spin up to blow away heat when your laptop or desktop is running a compute-intensive program. And if it's a laptop, notice how it warms up at that time. Regarding getting people to power off their PCs, the PC itself may do a pretty good job of that on its own. It goes into a low power state whenever possible, and depending on your power management settings, may also put itself on standby after some idle time.