2. What is grey energy?

Some objects, such as a refrigerator or a car, consume energy when they are used: electricity for a refrigerator, gasoline or diesel for a car with an internal combustion engine. For the user, this is the energy he or she needs to use the object throughout its life: this is operational energy. It is also sometimes referred to as direct energy.

Grey energy doesn't just concern objects. It also concerns products, especially foodstuffs, services and even the production of energy itself, since energy was required to manufacture the devices needed to produce it. The manufacture of the object, its maintenance and the management of its end-of-life also require a quantity of energy that is rarely taken into account, as it is the responsibility of external economic agents such as the manufacturer, transporters, repairers or waste managers. This energy, known as grey energy...