Mercury vapor lights, also known as mercury lamps, do consume a significant amount of electricity compared to more energy-efficient lighting options available today. These lights operate by ionizing mercury vapor inside the lamp, which produces ultraviolet light that, in turn, excites a phosphor coating on the inner surface of the lamp, emitting visible light.
Mercury vapor lights have been used for various applications, such as street lighting, industrial lighting, and outdoor lighting. While they were once popular due to their long life span and relatively high light output, their energy efficiency is relatively low compared to newer lighting technologies.
On average, mercury vapor lights consume significantly more electricity compared to alternatives such as fluorescent lamps, compact fluorescent lamps (CFLs), and light-emitting diode (LED) lights. This is primarily because mercury vapor lights have lower luminous efficacy, meaning they produce less visible light per unit of electrical power consumed. Additionally, a portion of the electrical energy is also lost as heat in the process.
Due to their inefficiency and the presence of toxic mercury vapor within the lamp, many countries and regions have phased out or restricted the use of mercury vapor lights in favor of more energy-efficient and environmentally friendly options like CFLs and LEDs. These newer lighting technologies offer improved energy efficiency, longer lifespan, and reduced environmental impact.