Embodied energy is the energy that is consumed in order to build a given usable object. This includes the energy from material extraction, refining, processing, transporting, and fabricating. It is named as such because it is as if this energy is "embodied" within the item itself. Embodied energy also comes along with idea of embodied carbon, which is the associated CO2 footprint that is emitted during the object's creation.
Embodied energy is found within all types of objects, including things like cell phones, appliances, homes, buildings, and furniture. The embodied energy of a given object can be analyzed by knowing what materials are contained within an object, and how much of that given material there is. The amount of energy needed to produce a certain material such as aluminum, steel, or concrete is known and can be used to calculate the embodied energy within an item.
The idea of embodied energy is important to help analyze the energy savings of a particular object. For example, if a proposed wind turbine is promised to be more energy efficient in its operation but requires tremendous amounts of energy in its materials and assembly, it might not be worth the effort. From this knowledge of an object's embodied energy, the environmental impact associated with it may also be estimated.
The embodied energy within a given raw material is typically measured in an "energy per unit mass" scale, such as megajoules per kilogram. For the table below the values are an aggregate of all of the energy within the objects, so there is no mass unit included, rather it is the amount of energy in the entire object.
|Item||Embodied energy (MJ/functional unit)|
|Item||Embodied energy (MJ/kg)|