You might think that, next to gas-guzzling cars, emissions-spewing factories and giant jet aircraft, your home computer was the least of the world’s worries when it came to damaging the environment. You’d be mistaken.

An enormous amount of energy is wasted by PCs and associated devices left on standby around the clock, and by printers spewing out barely used paper. Computers and gadgets consume about 15% of household electricity, according to the Energy Saving Trust, and, as we become ever more technologically reliant, the figure is likely to rise to nearly half by 2020.

There are several ways to moderate your equipment’s energy appetite without affecting day-to-day computing. They range from cutting power requirements to picking more energy-efficient equipment and disposing of old electronics safely.

SWITCH OFF

How many times have you gone to an hour-long meeting or popped downstairs to watch the TV while leaving the desktop running? A modern home computer runs at about 175 watts when sitting idle, the equivalent of leaving the light on in three rooms of your house.

Windows has power-saving settings that can be easily tweaked to keep the waste to a minimum. In Windows XP, click Start, Control Panel, then Power Options. You’ll be presented with various options to turn off your hard disk and monitor – set both to switch off after 10 minutes of inactivity.

You’ll also see two options to put the PC into Standby or Hibernation. Standby keeps the computer churning in a low-energy state, ready to resume quickly when you return. Hibernate sends the PC into a deeper sleep, in which it consumes almost no power but takes a little longer to wake up. Set Standby to kick in after 15 minutes and Hibernate after 30 to provide a balance between energy-saving and convenience. For more tips on Windows power-saving, visit tinyurl.com/45ryb .

If you don’t like the idea of altering Windows settings yourself, download the free Local Cooling software (www.localcooling.com ), which will automatically apply power-saving settings for you. It also gives you a green glow inside by showing how many trees, gallons of oil and kilowatt hours of power you’ve saved since installing the software.

It’s all well and good switching off the PC before popping out for a pint, but what about the printer and assortment of other connected gadgets? If you plug the mains cables of all your peripherals into the OneClick Intellipanel (£30 from www.oneclickpower.com/acatalog ), it will detect when your PC shuts down and withdraw the power to all the other devices. It builds in a five-second delay to allow printers to go through their shutdown routine and also includes surge protection.

MINIMISING PRINTER WASTE

Printers are one of the worst environmental offenders: not only do they sit idle with power on in homes and offices all day, but when they are called into action they print on only one side of the paper.

Most people don’t realise that even cheap home inkjet printers, such as the excellent Canon Pixma ip4500 (£72 from Amazon), boast the “duplex” feature that allows them to print on both sides. Even if your printer doesn’t support automatic duplex, it’s still possible to print on both sides by tweaking your word-processing software so that it sends only odd pages, then, after you have reinserted the stack of pages, the even-numbered pages. The helpful guide at tinyurl.com/24qwlu reveals how to set up double-sided printing in Microsoft Word.

Not only is printer ink heinously expensive, but it’s often splashed lavishly onto pages that are for your eyes only and therefore don’t need to be top quality. All printers have a draft-mode setting that saves ink by making the printed page fainter but still perfectly readable. Click Start, Control Panel, Printers, then right-click on your printer’s icon and select Printing Preferences to adjust your printer’s output to draft or economy mode.

Visit tinyurl.com/yqlc7q for more ink-saving tips, and never believe your printer when it tells you it’s running out of ink – there’s usually plenty more in the tank after the warnings start appearing.

When cartridges do run dry, don’t sling them in the bin – all the leading manufacturers offer cartridge recycling. Check the cartridge’s packaging for postage instructions. Alternatively, the Recyling Factory (www.therecyclingfactory.com ) buys and sells used and recycled cartridges, offering credit for old cartridges sent back by freepost against purchases of new ones. Check the website to see whether your cartridge is compatible (not all brands are).

BUYING GREEN GEAR

Modern PCs have more processing power than most people need, and they waste huge amounts of energy as multiple fans whirr away to prevent the system from overheating. Laptops are vastly more energy efficient than desktop computers, but for those who prefer a full-size screen and keyboard, there are greener alternatives.

The British PC makers Tranquil (www.tranquilpc.co.uk ) and VeryPC (www.very-pc.co.uk ) specialise in energy-efficient computers; VeryPC’s GreenPC Treeton consumes an average of just 30 watts thanks to its laptop-style components.

What’s more, VeryPC will give the Treeton a spring clean at the end of its three-year warranty, ensuring that dust doesn’t hamper the cooling technology and extending the life of the machine.

If you prefer to stick to the big-name brands, make sure you read Greenpeace’s guide to greener electronics (www.greenpeace.org/greenerelectronics ) before buying. This regularly updated league table ranks companies according to their environmental commitments, such as the removal of dangerous chemicals and recycling.

If you’re browsing for products on the high street, keep an eye out for the Energy Star logo (www.energystar.gov ). This certifies all manner of office equipment – from monitors to printers and PCs – based on power consumption, ensuring that they operate efficiently, that computers are preset to enter standby modes after 30 minutes and that wasteful screen savers aren’t installed.

DISPOSING OF OLD EQUIPMENT

Since last year, technology manufacturers and retailers have been forced to foot the bill for recycling old computers and gadgets. This is the result of a ruling by the European Union known as the WEEE directive (you can read more about it at tinyurl.com/yuzs6j ).

As a result there are now nationwide schemes that collect electronic waste from council-run sites. The postcode checker at www.recycle-more.co.uk will reveal where your local collection points are, and what type of electronic waste they’ll accept.

More often than not, the PCs we dispose of are still in working order, and even arranging for them to be recycled safely seems a waste. Organisations such as Computer Aid (www.computeraid.org ) accept old PCs from businesses and individuals, to be refurbished and sent to projects in developing nations. The rather more ad hoc Donate a PC (www.donateapc.org.uk ) aims to match computer donors and needy organisations in the UK.

Before sending any computer to be refurbished, check whether the organisation securely wipes the data from your hard disk first. Don’t fall into the trap of formatting your hard disk and believing your data is safe – it can still be recovered.

The widely respected Blancco Data Cleaner + (£17 from www.blancco.com ), which is used by organisations such as Computer Aid, will ensure all personal data is wiped permanently.

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