Even without recycling of waste lamps, using CFLs releases less mercury into the environment than using incandescent light bulbs. This is because burning coal to produce electricity releases mercury. CFLs use only about 20 per cent of the electricity that incandescent bulbs use to produce the same amount of light, therefore requiring less electricity to be generated. The result is that use of CFLs releases about 80 per cent less mercury than incandescent light bulbs.