yes.. look ate wattage on the back of the components. You will be surprised..
A 400 watt power supply in the CPU and a 130 watt monitor plus the laser printer that uses about 200 in idle.. Or, if you have a Phaser color printer that sits there using around 330 watts in idle. Add in the power used by your power conditioner/backup. It don't take long to use up $30 bux a month in power..