In the early 1990s, it was estimated that there were more than one billion external power supply active in the U.S. alone. The efficiency of these power supplies could be as low as 50% and still draw power when the application was turned off or unconnected (a [no-load" condition). Experts calculated that without efforts to increase efficiencies and reduce no-load power consumption, external power supplies would account for around 30% of total energy consumption in less than 20 years. As early as 1992, the US Enironmental Protection Agency started a voluntary program to promote energy efficiency and reduce pollution, which eventually became the Energy Star program. However, it was not until 2004 that the first mandatory regulation dictating efficiency and no-load power draw minimums was put in place. Fugure 1 demonstrates just how dynamic the regualtory environment has been over the past decade. It also teaces th path from the CEC's 2004 regulation up to the new DoE level VI standards that went into effect in early 2016. It also shows the European Union's code of Conduct standards that are voluntary now, but are currently under review to become Ecodesign requirements in two tiers. The tier 1 standard, which is broadly equivalent to level VI, is proposed to become mandatory sometime in 2017 and the tighter Tier 2 standard is proposed to because mandatory in 2018.
While many countries still have voluntary programs harmonized to the international efficiency marking protocol system first established by the ENERGY STAR Program, the U.S., Canada, and European Union now have mandatory energy efficiency regulations in place for external power supplies.
Power supply manufacturers such as Pengchu prepared well in advance for the transition to the more stringent level VI standards. Along with tightened regulation for existiong adapters, the standard expanded the range of regulated products. It should be noted that the current voluntary EU CoC Tier 1 requirements are broadly equibalent to DoE level VI.