What is a Discharge Lamp?
Also called a “gas discharge lamp, a discharge lamp discharges an electric arc through a mix of gases and gaseous metals to produce light.
Gas Discharge vs. Heating a Filament
Incandescent bulbs light up by heating a filament. It certainly does the job, but the one downside is that much of the energy consumed by incandescent bulbs is used to produce heat, which means less energy is for the ultimate goal: producing light. While discharge lamps such as HID bulbs are still not as energy-efficient as LED lamps, they do put energy to a more focused use than incandescent bulbs do. Additionally, the gas used in discharge lamps can vary in order to produce varying colors of light.