Megawatt-hour (MWh)

A megawatt-hour measures energy: an amount of electricity. It is one megawatt of power delivered for one hour, or 1,000 kilowatt-hours.

Also called MWh

Formula

1 MWh = 1 MW × 1 hour = 1,000 kWh

With real numbers37.14 TWh = 37,144 GWh = 37,144,415 MWh

37.1 TWhVogtle in 2025, the most energy of any US plant

Vogtle has 4,658 MW, less than Grand Coulee's 6,809 MW, yet it made 37.1 TWh in 2025 against 16.2 TWh. It ran near full output almost all year.

Net generation in 2025, TWh

EIA-923 net generation, 2025, for the six largest plants by nameplate MW.On the map

Built from InfraMap's 2025 data with the same tools the analyst uses.

Multiplying MWh by hours again. An hourly or monthly MWh figure is already an amount, so multiplying it by time counts it twice.
Ranking plants by MW when the question is energy. The plant with the most MW is not always the one that makes the most MWh, as the chart below shows.
Mixing gross and net generation. Net MWh subtracts what the plant uses to run itself, and gross MWh does not.

An amount of electricity produced, consumed or stored. Already integrated interval MWh must not be multiplied by interval hours again.

1 MWh = 1,000 kWh; 1 GWh = 1,000 MWh

Reviewed October 1, 2026 against the references below. The analyst and the MCP server answer with this definition.