Feature: Sensible approaches to green computing

Nearly all the high-drain devices in a home (dish washers, vacuum cleaners, microwaves, electric showers, kettles and washing machines) are used for only short periods so there is little scope for using them more economically apart from choosing the most energy-efficient models when the time comes to replace them.

By law, multi-coloured EU energy labels must be attached to all domestic appliances, rating them from A++ to G, where G is the most power hungry. By choosing equipment in the A bands you'll be doing yourself, and the planet, a big favour.

Unfortunately, computing and home entertainment equipment is not tagged with the same easy-to-understand energy labels, but it's a sobering fact that many wide-screen plasma TVs consume more power than a fridge-freezer.

If you have a plasma TV, do you turn it off when you're not watching it? Significant savings can be made simply by switching things off when you're not using them: everything from DAB radios to electric lights.

The same goes for computer equipment, which is sometimes left running overnight when downloading from the internet or backing up data. If the PC is performing a lengthy operation, at least turn off the monitor.

Standby for action
Turning off devices when you're not using them makes sense, but when you turn something off, is it really off? The switches on many electronic devices merely set them into standby mode where they consume a reduced amount of power, but are ready to respond to commands from a remote control unit.

Standby power is also used to keep internal clocks ticking and to store user options and presets. Many of you wrote to us after we mentioned this issue on out letters page to point out that the amount of power consumed in standby is small compared with, say, running a hot-cycle wash.

But again, it is the cumulative consumption, multiplied by millions of households around the UK, that poses the problem.

While standby mode is preferable to leaving a device fully powered, research conducted around the world has revealed that vast amounts of power are wasted by devices left in standby mode. In Australia, a staggering 13 per cent of the country's domestic electricity consumption is consumed in this way. While the UK figure is rather lower at 6-8 per cent, it is still significant.

When in standby mode, many appliances consume just a few watts, but some televisions, DVD recorders and set-top boxes use up to 15W, and there are compact Hi-fi systems that draw up to 25W per hour. The only way to be sure how much energy your equipment uses, both in fully operational and standby modes, is to measure its power consumption using an energy meter.

You won't find these alongside the light bulbs in your local supermarket, but good electrical retailers have them, or you can order a basic model online from Maplin for £27. Plug it into a mains socket, then plug in the equipment you want to monitor and read off its power consumption from the digital display.

The only way to completely disable such devices is to switch them off at a wall socket, but for devices that need internal clocks, that's not always practical.
Having identified where the power goes in your home, you can take action.

Obviously you won't want to completely switch off any device that has an essential timer, such as a video recorder, but there's no reason not to power down other devices when they're not being used.