No load power
No load power consumption is the electric power consumed by a power charger when it is plugged into a wall socket but without the mobile phone or other handheld device being connected.
This wasted power is often wrongly labelled as standby power but standby refers to the power consumed by a power adapter when a device such as a TV, DVD recorder or audio system is in a lower power mode that cannot be switched off (or influenced) by the user. The power consumed in standby mode is used to maintain essential system functions such as remote control operation or a digital clock. Whereas the no-load energy consumed in a power charger is of no practical use.
Consequences
The no-load power contribution to a country’s household energy demands is thought to be considerable [1]. The average number of handsets per capita is frequently more than one in many countries [2], the proportion of chargers left accidentally or deliberately plugged in is thought to be significant and with current designs over 60% of a mobile phone’s energy use is wasted as no-load [3].
As a result mobile phone manufacturers have become increasingly focused on reducing the no-load consumption of their power chargers. For example in 2002, a typical design might use about 3 watts on average and in 2007 less than 0.5 watts ,[1].
Policies to reduce no load power
Energy Star, the EU code of conduct on standby and other mandatory and regulatory standards are encouraging manufacturers to make further reductions in no-load energy demands.
For example: under the Energy Star V2.0 (level V) voluntary standard introduced in November 2008 the no-load consumption of a typical 4.25 W charger has to be less than 300 mW (0.3 watts). The EU code of conduct version 4, introduced in January 2009 has a limit of 0.25W for mobile handheld battery driven applications, reducing to 0.15W in January 2011. Complete list of national and international standards.
5 star rating system
In November 2008, the world’s five largest mobile phone makers – Nokia, Samsung, LG Electronics, Motorola and Sony-Ericcson - announced their own five star energy rating system to help consumers more easily identify the most energy-efficient chargers. Chargers are being labelled with no stars for no-load consumptions > 0.5 W and up to five stars for consumptions less than ≤0.03W (30mW).