How many lightbulbs does it take .....

From ENN --

Lighting is a relatively heavy demand on the electricity grid, taking up around 19 percent. Annual carbon generated because of this amounts to 1,500 million tonnes, equivalent to pollution of more than half of the world's light passenger vehicles.


ENN recently posted How Many Energy-Efficient Light Bulbs Does It Take to Close 705 Coal Plants?
worth reading in its entirety --

The second major advance in lighting technology is the light-emitting diode (LED), which uses up to 85 percent less electricity than an incandescent bulb. Although LEDs are the ultimate in lighting efficiency, they are still too costly for most uses. They are rapidly taking over several niche markets, however, such as traffic lights, where they now have 52 percent of the U.S. market, and exit signs in buildings, where they hold 88 percent of U.S. sales. New York City has replaced traditional bulbs with LEDs in many of its traffic lights, cutting its annual bill for maintenance and electricity by $6 million. In early 2009, Los Angeles Mayor Antonio Villaraigosa said the city would replace its 140,000 street lights with LEDs, saving taxpayers $48 million over the next seven years. The resulting reduction in carbon emissions would be like taking 7,000 cars off the road.