There is a lot of attention of late regarding residential fluorescent lighting. The advent of these compact fluorescent lamps (CFL) has revolutionized options for residential lighting. The primary source of residential lighting for years has been the standard incandescent lamp and, to a lesser degree, the halogen lamp (for track lighting, etc.) A byproduct of any lighting source is heat. A measure of the efficiency of a lamp is how much energy is converted to light and how much to heat.
Anyone who has grabbed a hot incandescent lamp can tell you just how hot they can get (Ouch!!). This is a good indication that a great deal of the energy consumed by these types of bulbs goes directly to heat instead of light. In fact, these lights produce heat by a process of electrical resistance, the same principal used by a toaster or hair dryer. This is primarily a heat producing process with light as a byproduct.
Fluorescent lamps work on a much different principal. They work by electrically exciting a gas inside the glass to the point where it fluoresces (or lights up).
Fluorescent lights are 4-5 times more efficient than incandescent lights of the same light output (lumens). As a result you can replace a 100 watt incandescent bulb with a CFL having similar or better light output and which consumes only 20-25 watts.
This has two benefits: First it reduces your primary lighting cost as discussed. Secondly it reduces your cooling cost. Any heat produced by a light must be removed by your air conditioning system.
Modern compact fluorescents are made to fit virtually any fixture, however, some care must be taken on certain fixture types (3-way lamps, dimmer applications) to match the CFL with the application. Fluorescent doesn't have to be boring. Fashionable designs with energy efficiency in mind are made by Hinkley Lighting and Murray Feiss Lighting.
Although in theory, these CFL’s offer very attractive savings, the fact that most residential lights aren’t used many hours per day makes the actual payback on purchasing the CFL occur 2-3 years later. However, the significantly longer life of a CFL over a standard incandescent helps recover actual cost much sooner.
Although still quite rare and more difficult to find, a new technology called LED lighting is a promising technology. LED lights are even more efficient that fluorescents without some of the size and shape restrictions seen in a fluorescent. LED lights (Light Emitting Diode) produce very little heat as a side effect and have a very long life.