Regular incandescent light bulbs require about 25 to 100 watts. More energy-efficient light bulbs require fewer watts to provide similar light. A compact fluorescent bulb needs just a few watts to light up.

A kilowatt (kW) is equal to 1,000 watts. A kilowatt of power is about equal to the average annual electrical consumption of a single household in the United States for an entire year.

A megawatt (MW) is equal to 1,000,000 watts. Electrical generators at utility companies output so much power that it’s measured in megawatts. The hydroelectric generators at Hoover Dam produce over 2000 MW collectively.