energy is the capacity
A utilityâs capacity is calculated by totaling the capacity of each plant it owns and other contracted capacity it may have secured. Energy. Energy is the amount of electricity (produced from capacity) customers consume over time. Energy is measured in megawatt-hours (MWH). Unlike capacity, each of us consumes or uses energy. When you turn on a light, plug in a computer or cool a home, you consume energy. Retail marketing of electricity.