Whilst many PCs have energy-saving modes there's clearly room for improvement in these days of high energy prices and greater green awareness. That's where Edison comes in.

Edison is a handy program from software vendor Verdiem that monitors and controls your home PC's energy consumption. You can set the energy-saving modes for when you work from your PC and for non-work times, so if you work on your laptop from 9:30am to 5:30pm, just program these times into Edison.

By default Edison turns off the display, powers down the hard-drive and suspends the computer after 15 minutes in work mode, allowing you to work without power-management interruptions. Non-work mode turns off the display and powers down your PC's hard-drive after 5 minutes and suspends the computer after 10 minutes, although this is all configurable from Edison's power management panel.

Edison also shows you how much CO2 and money you're saving by powering down although, for us Brits, this feature is in U.S. dollars. And at $0.089 per kWh I'm not sure whether Americans get a better rate than us, although you can set the rate. (Use xe.com to convert dollars to your local currency)