Incandescent lights are the most commonly used form of lighting. This includes the standard everyday light bulbs and halogen downlights. On the offset, they are inexpensive to buy but their lifetime running costs quickly add up.
An incandescent light creates light by running electricity through a filament, which heats up and then literally glows white-hot. It is a very inefficient way of creating light as 90% of the electricity used is turned into heat with only 10% being turned into light.
Incandescent lights are very dangerous and are a fire hazard with halogen lights being responsible for most household fires. The filaments in halogen lights rise up to 2,500°C and the bulb up to 500°C. The temperature at which paper will ignite without a spark or flame is 230°C, so if there is any insulation touching the light fitting a fire can easily start.
Because incandescent emit so much heat, your cooling system needs to work harder to compensate amounting to extra costs in energy bills. The lamp life of an incandescent is only an average of 1,000 hours making regular replacement necessary which wastes money on maintenance costs. It is also very impractical in hard to reach places such as high ceilings.
The most simple alternative to halogen lights is to replace them with the more efficient IRC lamps. They are virtually identical to standard halogens, only the bulb has an Infa Red Coating that reflects some of the heat back into the filament. Lamp life is extended by up to 4,000 hours and will save up to 30% of energy in comparison to a standard halogen. Although the fire hazard still remains and much greater energy savings can be achieved with other options such as LED's and CFL's.