What’s wattage?

Wattage specifies the energy consumption of a light source but says nothing about the amount of light it produces. Specified in W (watts). Wattage (W) specifies the energy that the light source uses per unit of time. For fluorescent lamps, other discharge lamps, low-voltage halogen lamps and LED lamps, there is also the energy consumption and energy losses of the driver. The total wattage is often referred to as the system wattage.