Let's begin with America's most used, Compact Fluorescent Lamps (CFL). Although, energy-saving, its hazardous components have raised a ton of questions on the sustainability of its use. The U.S. Environmental Protection Agency estimated that if all 270 million CFLs sold in 2007 were sent to landfill sites, around 0.13 metric tons of mercury would be released, 0.1% of all U.S. emissions of mercury (around 104 metric tons that year).
'The Granddaddy' of lighting, the incandescents have lit our homes for centuries. However, Its primitive technology is known for its disregard of energy efficiency and a terrible lifespan. Of the power consumed by typical incandescent light bulbs, 95% or more is converted into heat rather than visible light.
We have seen great leaps in lighting technology and LED (Light Emitting Diode) lamps are a product of that. They have a lifespan many times longer than equivalent incandescent lamps and are significantly more efficient than most fluorescent lamps. Additionally, they come to full brightness immediately with no warm-up delay. Frequent switching on and off does not reduce life expectancy as with fluorescent lighting.