Nokia, Samsung, Sony Ericsson, Motorola and LG Electronics have now launched a new ratings system covering all chargers they currently produce, ranging from five stars for the most efficient chargers down to zero stars for the ones consuming the most energy.
Nokia admit that around two thirds of the energy used by mobile devices is ‘lost’ when chargers are disconnected from the phone but left plugged into the mains. This is known as 'no-load energy consumption'.
The manufacturers claim they are improving the efficiency of their (branded) chargers and the use of this energy rating system should help consumers to pick the ones that use the least energy. (Most of the industries chargers are actually produced by a small number of 3rd party OEMs.)
A Nokia press release with details of the rating system can be found at http://www.nokia.com/A41389016.
For example, Nokia claim that their current charger models have the following energy ratings and No-load power consumptions:
5* Charger Model AC-8 < 0.03W
4* Model AC-3 < 0.15W
4* Model AC-6 < 0.15W
2* Model AC-4 < 0.3W
2* Model AC-5 < 0.3W
Nokia state that the actual No-load consumption per year (based on a use case when a phone is being charged for 3 hours twice a week, while at other times the charger is not connected to a phone but still plugged in an electric outlet), are as follows:
300 mW charger (eg Nokia's Nokia Travel Charger AC-4 or AC-5) = 2527 Wh
150 mW charger eg AC-3) = 1264 Wh
30 mW charger (eg AC-8) = 253 Wh
In other words, the most efficient chargers have a No-load consumption which is a fraction of their less efficient siblings.
“If the more than three billion people owning mobile devices today switched to a four- or five-star charger, this could save the same amount of energy each year as produced by two medium sized power plants,” Nokia claimed in a statement.
Of course, it is generally only the high-end handsets that ship with the most energy efficient chargers. The best way to make a difference to global energy consumption may be for Network Operators to require manufacturers to bundle energy efficient chargers with mass market phone models, particularly those distributed in the fast expanding emerging markets sector. Come on Vodafone & China Mobile ...
More information can be found at the various manufacturers websites:
Sony Ericsson: http://www.sonyericsson.com/cws/corporate/company/sustainability/energy