May 1, 2010 is what the Environmental Protection Agency--the federal bureau that oversees the Energy Star project--calls the new requirements' "effective date." No televisions manufactured on or after that date will be able to carry an Energy Star logo unless they are 4.0 compliant. If a particular model is only 3.0-compliant, a unit built on April 30 could have the logo, but not one built the next day.
In addition, such models will disappear from the of compliant televisions as of that date. Meanwhile, the EPA's list will continue to be updated with 2010 models that are compliant.
The outgoing 3.0 specifications were not particularly strident. A 50-inch set could consume a full 318 watts when turned on and still get to display the logo.
By comparison, Energy Star 4.0 means a 50-inch HDTV will not be able to carry an Energy Star logo if it burns more than 153 watts--just shy of half 3.0's maximum.
The new specifications also require that a set use less than a single watt when in sleep or standby mode--usually referred to colloquially as being "turned off."
While the change in energy consumption is a dramatic one, manufacturers are ready for the switch. Already, the 2010 models for Panasonic, Samsung, Sharp, Sony, and Vizio are Energy Star 4.0 compliant.
Television manufacturers don't have to comply with Energy Star rules to sell their wares in the United States, but they'll have to come close to that in California.
Last year the introduced regulations, going into effect at the beginning of 2011, that come very close to Energy Star requirements. Effectively speaking, only Energy Star sets will be sellable in the golden state.
Even more strident rules are on the horizon. Energy Star 5.0 becomes effective on May 1, 2012. When that happens, a qualifying 50-inch set will have to burn no more than 108 watts when on. So will a 60-inch set, since the EPA has decided that, for 5.0, the maximum consumption for 50 inches will be the maximum, period.
By comparison, according to the Energy Star 3.0 specs, a 32-inch set can burn more than that.