External power adapters have come a long way in energy efficiency, so much so that effective December 31, 2010, they'll will no longer be eligible for the Energy Star label, say EPA officials who administer the program.
External power adapters come with products like digital cameras, cordless phones and cell phones. EPA figures there are about nine external power adapters for every person in the U.S. – as many as 2.7 billion in total. External power adapters were originally added to the Energy Star program in 2005 as a way to address energy waste across the broad array of diverse products powered by them. At the same time, EPA specified the use of Energy Star qualified adapters for relevant product categories that were covered by the program.
Within 3 years, approximately 50% of all external power adapters sold in the U.S. were Energy Star qualified, saving 5 billion kWh per year. In 2008, a federal minimum efficiency standard went into effect for adapters, mandating the Energy Star performance level. EPA strengthened the Energy Star requirements further and by 2009, estimates indicated that the market share of external power adapters meeting the new Energy Star specification was greater than 50%.
More information on adaptors: http://www.energystar.gov/eps_sunset