Watts to Megawatts Converter

The watt is the SI unit of power: one joule of energy transferred each second. Its symbol is W, and it is the base from which every larger power unit is built.

Watt ratings appear on light bulbs, televisions, kettles, solar panels, inverters and small generators. Physics and engineering use the watt for every rate of energy transfer, from a laser to a motor.

Because power is a rate and energy is an amount, a watt multiplied by a duration gives energy in joules or watt-hours. Metric steps above the watt are exact powers of one thousand.

A frequent error treats the watt as a quantity of energy, so an appliance rating is read as consumption. Power needs a time period before it becomes an amount of energy.

Watts suit appliance and electronics figures, kilowatts suit generators, inverters and solar arrays, and megawatts suit grid capacity. Milliwatts cover indicator lights and small sensors. Reading a generator rating in watts rather than kilowatts multiplies the number by a thousand and misstates the scale.

A megawatt is 1,000 kilowatts, or one million watts, and it carries the symbol MW. Power at this scale is quoted in megawatts because a figure in kilowatts would run to several digits.

Grid-scale generating stations, industrial plants, large data centres and utility-scale solar farms are described in megawatts of capacity. Transmission and distribution planning also uses the unit for load forecasts.

A megawatt measures capacity, which is a rate, while a megawatt-hour measures delivered energy. One megawatt sustained for one hour therefore equals one megawatt-hour, or 3.6 gigajoules.

Reporting a plant's output as megawatts when the figure is megawatt-hours confuses capacity with production. The two differ by the operating time, so a megawatt figure alone says nothing about how much energy was generated.

Megawatts describe capacity at grid and industrial scale, while kilowatts describe the appliances and generators on the same site. The unit is also mistaken for the megawatt-hour, which is a sibling in the energy dimension; capacity and delivered energy are not the same figure.