Joules (or watts) is a measure of capacity. Electricity generating capacity, especially with intermittent sources like wind is almost meaningless. Who cares ab

Joules (or watts) is a measure of capacity. Electricity generating capacity, especially with intermittent sources like wind is almost meaningless. Who cares about capacity if the actual generation is zero. Watt-hours, Megawatt-hours, and terawatt-hours are used because that's the descriptive term of energy actually produced.