Process energy represents the energy services from capital stock used to produce output within each sector (housing for sustained living in residential, buildings to provide services in commercial, factories and industrial processes for producing output in industrial, and transportation infrastructure for transporting people in transportation). Process energy represents the building-level energy needs, such as heating and cooling. Process energy efficiency represents the building level efficiency and is impacted by insulation levels as well as consumers’ usage patterns.

Device energy represent the energy from specific energy-using equipment used to meet process energy requirements. For example, a light bulb provides the device energy required by households’ lighting or a car provides the device energy required by transporting needs.