Save money and power with your PC

You will find out that your computer and its peripherals are relatively light power users. Devices with a heating element, such as toasters, kettles and irons, draw far more power. For example, most kettles will draw in about 3,000W, which is around the same as 60 laptops. Of course, you would not leave a kettle switched on as long as a laptop each day, but make a few cups of tea a day and the costs soon mount up.

Power costs
Once the power draw of your computer is revealed, you can work out exactly how much it costs to run. Electricity companies charge by kWh; calculating this figure for your computer involves multiplying the power draw (in kilowatts) by the number of hours you leave it switched on.

For example, if the power draw is 125W, this needs to be first divided by 1,000 to convert it to kilowatts (in this example it’s 0.125kW). If the computer is then left on for five hours, this figure needs to be multiplied by five to get the kWh figure, which results in a total power usage of 0.625kWh. Assuming a price of 20p per kWh, it would cost 13p for each hour the computer is switched on.

Alternatively, UK Power has a useful online cost calculator where you can find the cost of typical household devices. You can also enter the power draw (in watts) of other devices to find out how much they cost to run. We focused on PC running costs in more detail on the last page of this feature.

Windows power management
Windows also has a few tricks up its sleeve to help reduce power consumption. Compared with Vista and Windows 7, XP’s power settings are fairly rudimentary. The Power Options tool in XP, accessed from within Control Panel, lets you choose a power scheme (for example Always On or Presentation).

You can then tweak the plan’s settings, such as when the monitor and hard disks should be switched off after a period of inactivity, as well as when (if at all) the PC should go into Standby or Hibernate mode.

The Power Options tool in Vista and Windows 7 is also found within Control Panel, but it allows a far greater degree of control over how your PC operates in terms of power consumption. There are three preset power plans to choose from: Balanced, Power Saver and High Performance (you may find your computer manufacturer has tweaked these and given them different names, and in Windows 7 the High Performance option is hidden by default).