Fast Company: How Many Lightbulbs Does it Take to Change the World? One. And You're Looking At It.

 Compact fluorescents emit the same light as classic incandescents but use 75% or 80% less electricity.What that means is that if every one of 110 million American households bought just one ice-cream-cone bulb, took it home, and screwed it in the place of an ordinary 60-watt bulb, the energy saved would be enough to power a city of 1.5 million people. One bulb swapped out, enough electricity saved to power all the homes in Delaware and Rhode Island. In terms of oil not burned, or greenhouse gases not exhausted into the atmosphere, one bulb is equivalent to taking 1.3 million cars off the roads.

How Many Lightbulbs Does it Take to Change the World? One. And You're Looking At It.