Which type of lighting is NOT known for energy efficiency?

Incandescent lighting is not known for energy efficiency due to the way it produces light. This type of lighting works by passing an electric current through a filament, which heats up and emits light. However, a significant amount of energy is wasted as heat rather than being converted into visible light, leading to poor energy performance.

In contrast, LED (Light Emitting Diode) and CFL (Compact Fluorescent Lamp) technologies are designed to be more efficient. LEDs use a semiconductor to produce light and consume a fraction of the energy compared to incandescent bulbs while lasting significantly longer. CFLs work by passing electricity through a gas-filled tube, producing ultraviolet light that is converted into visible light by a phosphor coating, which is also more efficient than incandescent bulbs.

Halogen lights, while slightly more efficient than traditional incandescent bulbs due to their design improvements, still rely on a similar principle of heating a filament and consequently also produce a considerable amount of heat. Therefore, in terms of energy efficiency, incandescent lighting stands out as the least efficient option.