Consumption and Demand: Consumption refers to the amount of electricity used by residents, industrial and business customers, etc., over time. This is measured in kilowatt-hours (kWh) on a customer’s bill, reflecting the total usage. Megawatt-hours (MWh) and Gigawatt-hours (GWh) are larger units of consumption. Demand refers to the amount of electricity used at a moment in time. It is measured in watts, such as kilowatts, Megawatts, Gigawatts. An electric grid is built to ensure that customers have enough power during times of highest demand (often called peak demand), rather than the total consumption of electricity.