Smartest Choices for the Environmental Understanding with Green Exam
We often evoke gray energy to demonstrate that the impact on the environment of a product for example, or of a material, is not limited to what composes it. Indeed, gray energy, “embodied energy” in English indicates the energy which is not seen, which is included in the material. From Green Exam you will know about it all.
Gray energy, hidden energy
Gray energy therefore corresponds to the amount of energy necessary to produce an industrial good or a material. It is present at different levels:
- when designing the product or material
- at the time of extraction of the raw materials
- when transporting these raw materials
- during the processing of raw materials and the manufacture of the finished product
- when the service is marketed
- during the use of the product or during the processing of the material
- at the time of recycling
The Institute for the Eco-responsible Design of the Building, the ICEB, defines gray energy as follows:
The gray energy of a material, equipment or service is made up of two gray energies over the entire life cycle outside of life in use.
They are non-renewable gray energy, i.e. process energy (supply of energy necessary in the processes implemented during the life cycle) of non-renewable origin and renewable gray energy, i.e. process energy from renewable sources.
Important data to measure the real impact of a product
The environmental impact constitutes the whole challenge of calculating gray energy. Because if we are now fully capable of constructing buildings that are more respectful of the environment and of products with a reduced carbon footprint, greenhouse gas emissions are still just as significant in the production phases. The Green Associate Exam explores all these aspects now.
In a pragmatic way since the building is the most energy-intensive sector and the second producing the most GHG after transport, it is on it that the specialists looked in priority.
The gray energy of a building is the sum of the gray energies of the materials and equipment that compose it, to which we add:
- The energy required to move these materials and equipment between the factory and the site.
- The energy consumption of the site complementary to that already integrated in the gray energy of the components and equipment (base life, energy of implementation, transport of people).
- Gray energies linked to the renewal of materials and equipment which have a shorter lifespan than that of the building.
- The energy necessary for the deconstruction of the structure.
- It does not include maintenance (cleaning and minor repairs).
The gray energy is calculated by adding the primary energy consumed at each of these stages in the life of an industrial product or a building material: the extraction of raw materials, the stages of transformation, packaging, placing implementation, recycling, destruction and all transport used at each stage. Gray energy is expressed in kilowatt hours (kWh).
Examples of gray energy from different materials:
Gray energy often accounts for two-thirds of overall energy consumption. The fashion for the consumption of disposable products is therefore definitely to be avoided! It is in your best interest to use a product as long as possible to “make profit” from your gray energy. So, it is better to favor quality products, which will last longer over time.
