Canonical Definition
A megawatt-hour (MWh) is a unit of electric energy equal to one megawatt of power sustained for one hour, or 1,000 kilowatt-hours. It is commonly used in wholesale electricity markets, generation reporting, and large commercial or industrial billing. Residential customers are billed in kWh, but a typical US household consumes on the order of about 10 MWh of electricity per year.
Explanations
A megawatt-hour (MWh) is a big unit of energy. It equals 1,000 kilowatt-hours (kWh), the unit on your home bill. Power companies and markets use it to count what big plants make and sell. For scale, a normal US home uses about 10 MWh in a year.
A megawatt-hour is a big bucket of energy. It equals one thousand of the units on your home bill. Power companies use it to count the power they make and sell.
Analogy Bank
A megawatt-hour is like buying flour by the pallet instead of the bag — it's 1,000 of the kWh units that appear on a home bill.
Wholesale markets trade energy in MWh the way produce wholesalers deal in truckloads, while your receipt at the store lists individual items.
If a kilowatt-hour is a single brick, a megawatt-hour is a stack of a thousand bricks.
Do Not Say
- ✕Do not quote wholesale MWh prices as indicative of a customer's retail rate; those are different markets.
- ✕Do not state a household's annual usage as a fixed figure; the roughly 10 MWh average varies widely by home and region.