Not content with this, Nokia has started adding a feature to its phones so that when they are fully charged you get a message on the screen suggesting you unplug the charger from the mains.
There is an internationally agreed system for designating the efficiency of these plug-in power supplies - Roman numerals I to VII with one being the least efficient - and from December 1 2008, and April 1 2009 in New Zealand all plug-in power supplies manufactured or sold in Australia and New Zealand and designed to supply a single low DC voltage at up to 250watts will be required to conform to level 'V' efficiency and to be so marked.
The new Australian & New Zealand Minimum Energy Performance Standard (MEPS) requires that power supplies rated at less than 10 watts output should consumer less than 0.5 watts in standby and should be at least 50 percent efficient (ie if they deliver 10 watts to the device they are powering they must draw no more than 20 watts from the mains). At the top end of the scale 250W devices must be at least 84 percent efficient and draw no more than 0.75 watts in standby mode. For devices in between the required efficiency required increases progressively with the rated power output.
For this information about the new standard. I am indebted to D-Link which announced last week that all products it sells in Australia and New Zealand with external power supplies conform to the forthcoming standard and have done so for several years.
Good on them. And it shows they are more on the ball than a rival vendor (who I won't name) which made a great fuss about its green credentials recently, including a rather vague statement about the improved efficiency of its power supplies. When I asked for clarification they had to forward my enquiry to people in the US who, I was told, had to refer to engineers in China! I never did get a response. Moral: If you are going to brag about your green credentials make sure you understand them first.