There is a new standard for Led bulbs

 
   A new federal law introduced January 1, 2011 in California sets standards for the energy efficiency of incandescent light-bulbs sold in the state.
   The law, resulting from the Energy Independence and Security Act of 2007 (EISA), is designed to reduce energy use and associated pollution and make the United States less dependent on foreign sources of energy. It will save California consumers money with new led bulbs that offer the same amount of light while using less power.

   While the country will adopt this standard on January 1, 2012, California was given authority to implement the national standards one year earlier. It is estimated that this will avoid the sale of 10.5 million inefficient 100-watt bulbs in 2011, which would cost consumers $35.6 million in higher electricity bills, according to the California Energy Commission (CEC).

    The standard in California states that a 100-watt bulb manufactured on or after January 1, 2011 must use 28% less energy (i.e. a 100-watt bulb may not use more than 72 watts) in order to provide the same amount of light (in lumens).

   New led lighting technology has become more efficient than old-fashioned incandescent bulbs. Approximately 90% of the electricity used by traditional incandescent bulbs is wasted as heat instead of visible light. Replacing traditional incandescent light bulbs with more efficient halogen, compact fluorescent bulbs (CFL) or LED bulbs will save consumers money while still offering same amount of light. 

   The standard does not affect the existing supply of incandescent light bulbs stocked in retail stores or incandescent light bulbs already in use.

  The new standard is technology neutral and allows consumers to choose among a variety of high-performance products for their replacement lighting. The CEC press release mentions halogen, CFLs and LED lamps.

    A new standard covering 75W lamps will be introduced in California on January 1, 2012, and standards for 60W and 40W lamps will follow one year later.

More information on the changes is provided by the CEC and by the US Department of Energy.