Light bulb

Figure 1. An incandescent light bulb

A light bulb is a device that converts electrical energy into light. Modern incandescent light bulbs (see figure 1) are highly inefficient, with about 90% of the energy supplied to them being lost as heat. This inefficiency sparked a need for a variety of more efficient electrical lights, which spawned several alternatives to the traditional incandescent light bulb. These include:

• LED light bulbs
• CFL light bulbs
• Halogen lights