How do light bulbs compare for energy efficiency? Learn how much energy each type of bulb consumes.
Incandescent light bulbs – Old standard energy efficiency
Conventional incandescent light bulbs are energy hogs compared to other lighting choices. Just 1/10th of the energy consumed by incandescent bulbs becomes light. The rest of the energy is wasted as heat. Heat released by incandescent bulbs can help warm a room in winter, but adds to the cooling burden in the summer. Rooms lit with incandescent bulbs require more air conditioning, and more energy, to cool.
Halogen incandescent light bulbs – Better energy efficiency
Halogen incandescent light bulbs consume 25% less electricity and last nearly three times as long as conventional incandescent light bulbs.
Fluorescent lights and compact fluorescent light bulbs (CFLs) – Very good energy efficiency
Fluorescent bulbs, whether in conventional long tube shapes or spiral versions shaped to fit a standard socket, use 75% less energy than conventional incandescents. Fluorescent bulbs contain a small quantity of mercury, which is a hazardous substance and requires special handling when the bulbs burn out.
Light emitting diode (LED) bulbs – Best energy efficiency
Light emitting diode bulbs (LEDs) consume nearly 80% less energy than traditional incandescent. These bulbs are currently the most expensive lighting choice, but they have the longest lifespan, lasting nearly 25 times longer than ordinary incandescents.

