Learn About LEDs : ENERGY STAR.
As Participants in the Energy Star Program, we encourage you to understand the cost of the energy lighting the bulb alternatives.
How are LED lighting products different from other lighting, like fluorescent or incandescent?
LED lighting is more efficient, durable, versatile and longer lasting than incandescent and fluorescents lighting. LEDs emit light in a specific direction, whereas an incandescent or fluorescent bulb emits light — and heat — in all directions. LED lighting uses both light and energy more efficiently.
For example, an incandescent or compact fluorescent (CFL) bulb inside of a recessed can will waste about half of the light that it produces, while a recessed down light with LEDs only produces light where it’s needed — in the room below.

Pingback: Progress in Energy Efficiency Projects Pays Off « The Green Dandelion