All HID light bulbs are rated to last longer than halogen lightbulbs. According to the California Energy Commission, halogen bubs can last between 2,000 and 6,000 hours. MH lights can last between 10,000 and 15,000 hours. HPS lights can last between 12,000 and 24,000 hours.
Lumens are used to measure light intensity. HID lights produce more lumens per watt than halogen lights: 250-watt MH lights produce around 58 lumens per watt, 250-watt HPS lights produce around 87 lumens per watt and halogen bulbs only offer around 20 lumens per watt.
One of the only advantages that halogen lights have over HID lights is the fact that they contain no elemental mercury: 250-watt MH lights contain around 38 mg of toxic elemental mercury and HPS lights of the same wattage contain around 15 mg.
Unlike HID lights, halogen lightbulbs contain filaments that are typically made up of tungsten. Tungsten is used in the creation of filaments because it has a higher melting point than any other type of metal. Halogen lights emit light when their filament is heated to several thousands of degrees Fahrenheit.
Both types of lightbulbs have several practical applications. Halogen light bulbs are used to provide light in many homes. They are also used as headlights in many automobiles. HID lights are used outdoors to provide light for roads and parking lots. They are also used indoors in warehouse and greenhouse settings.