400megawatt

400 megawatt (MW) is a unit of electrical power equal to 400 million watts, or 0.4 gigawatts. It denotes a rate of energy transfer and is commonly used to describe the maximum continuous output of power plants, energy storage facilities, or large transmission assets. It is not a measure of total energy produced, which is expressed in energy units such as megawatt-hours (MWh) or gigawatt-hours (GWh). If 400 MW is sustained for one hour, it generates 400 MWh of energy.

In practical terms, 400 MW represents a mid-sized scale for grid assets. It may describe a single large conventional or combined-cycle power plant, a hydroelectric unit, or a wind or solar installation presented as a single project. The actual annual energy production depends on the capacity factor, which reflects how consistently the facility operates and at what fraction of its rated output.

For example, a facility with 400 MW of capacity operating at a 70% capacity factor would generate about 2.5 TWh of energy per year (400 MW × 8760 h × 0.70 ≈ 2.46 TWh). Higher capacity factors, such as those typical of hydro or baseload nuclear plants, yield correspondingly greater annual output, while lower factors reduce it, as seen with some renewable sources.

The term 400 MW is frequently used in energy planning, project announcements, and grid studies to convey the scale of generation or transmission capacity. It can also be expressed as 0.4 GW or roughly 536,000 horsepower.