Compact Fluorescent Lamp

LEDs are still the most expensive type of light bulb you'll see in the shops, but they do have advantages over the other types of bulbs. LEDs are the most energy-efficient bulbs. They use 90% less energy than traditional incandescents and can sometimes pay for themselves through energy savings in just a couple of months. So while the upfront cost might be high, you'll notice the difference in your annual energy bills. By contrast, Compact Fluorescent Lamps (CFLs) use 60%-80% less energy than incandescents, while halogens use 20-30% less. LEDs claim to be ultra long lasting - lasting for 25-30 years, depending on which one you buy and how you use it.
LEDs give out their light almost instantly when you flick the light switch, so you don't have to put up with dim light while they get going. Our tests have found that LED and halogen bulbs work fine in low temperatures, whereas CFLs don't.