Since fluorescent lamps use less power to supply the same amount of light as an incandescent lamp, they decrease energy consumption and the environmental effects of electric power generation. Where electricity is largely produced from burning fossil fuels, the saving reduces emission of greenhouse and other pollutants.
While CFLs require more energy in manufacturing than incandescent lamps, this is offset by the fact that they last longer and use less energy than equivalent incandescent lamps during their lifespan.
The chart shows the energy usage for different types of light bulbs operating at different light outputs.
Points lower on the graph correspond to lower energy use.