What isembodied energy ? Definition and uses

What isembodied energy ? Created in the 60s and intrinsically linked to research into product life-cycle analysis, this concept is designed to measure the overall environmental footprint of products, from the extraction of raw materials to their end-of-life. Particularly used in certain sectors, starting with construction, this methodology nevertheless suffers from certain limitations.

Matthieu Duault
Climate Copywriter
Update : 
April 1, 2025
Publication: 
March 19, 2024
Contents
Example H2
Request a demo

A concept dating back to the 60s, at the genesis of Life Cycle Assessment (LCA),embodied energy remains a measurement scale widely used in certain sectors of activity, and forms the basis of many environmental impact measurement systems. Sometimes placed in competition with the carbon footprint, these two methodologies are evolving in parallel and can prove complementary.

What isembodied energy and how is it measured? What and for whom is it useful?

The origins ofembodied energy

The term "embodied energy" first appeared in 1972 in the research work of Dr. Ian Boustead. The concept was the subject of several studies in the late 60s. Faced with the accumulation of waste and the massive exploitation of natural resources during a period of strong economic growth, many companies began to take an interest in the notion of product life cycles.

One of the first was Coca Cola, which in 1969 sought to identify less polluting alternatives to its glass bottle. The result, paradoxical as it may seem today, was that the plastic bottle proved to be much less embodied energy than the glass one. This goes some way to explaining the near-universal use of this format from the 90s onwards.

What isembodied energy ?

embodied energy corresponds to the total quantity of primary energy consumed throughout a product's life cycle, from the extraction of raw materials to its end-of-life. It is expressed in kWh.

This concept is designed to calculate the overall environmental impact of a product or material.

It therefore takes exhaustive account of the extraction of raw materials, transport, successive transformations, marketing, commissioning, use of the product and finally its recycling or destruction.

It is also known as embodied energy, or indirect energy, in the sense that it is not perceived by the consumer of the product or material. It is thus opposed to use energy, which is the energy consumed when the product is used (for example, the petrol you put in your internal combustion car or the heating of a building).

embodied energy is particularly useful in certain sectors, such as construction or household appliances. It enables us to draw up a balance sheet of the energy required to produce a building or a machine, and then to estimate when its construction has "paid for itself". In other words, its direct energy consumption has surpassed itsembodied energy consumption. According to this methodology, the longer a product's lifespan, the more likely it is to "pay for itself" in terms of its environmental impact, and thus avoid wasting energy.

Taking this subject into account seems all the more important as it is estimated thatembodied energy represents, on average, ⅔ of a product's total energy consumption.

Calculating its quantity would therefore enable you to know, for example, whether it's better to buy a new electric vehicle or keep your old gasoline-powered jalopy.

embodied energy and LCA

The notions ofembodied energy andLCA are interconnected. The term "embodied energy " was coined in connection with research into product life cycles. However, it was studies onembodied energy that subsequently led to the formalization and standardization of LCAs.

Product lifecycle analysis is a standardized, controlled method for quantifying theembodied energy of a product or service. The concept was first introduced at the Rio Earth Summit in 1992.

This methodology was then processed by the International Organization for Standardization (ISO), which created new standards, ISO 14040 and 14044, for measuring the LCA of products and services.

Use case example: construction

embodied energy has become a relatively common order of magnitude in the construction sector. It can be used to measure the environmental impact of a building, and is the source of many innovations, both in the choice of materials and in the construction process.

A building's embodied energy includes, in particular:

  • The energy used to manufacture building materials.
  • The energy used to transport materials to the site.
  • The energy used to construct the building.
  • Energy used to maintain the building.
  • The energy used to demolish the building.

Then there's the transportation of the workers, the setting up of the site, etc...

Since a building logically has a particularly long lifespan, it is estimated thatembodied energy represents on average 20% of the total energy consumed over its lifetime, which still represents a substantial part of its environmental footprint.

Possible solutions for reducing this amount of energy include those focusing on materials (sustainable, low environmental impact, local to reduce transport) and those involving building design (eco-responsible construction practices, energy-efficient buildings).

With this in mind, AFNOR has developed the HQE label, which aims to "limit the short- and long-term environmental impact of a construction or renovation project, while providing occupants with healthy and comfortable living conditions". This label is based on studies into theembodied energy of buildings, and takes into account, among other criteria, the energy that will be consumed throughout the life of the building.

The limits ofembodied energy

Whileembodied energy is supposed to measure the "global" impact of a product or service throughout its life cycle, its focus on energy limits the analysis, failing to take into account other co-impacts on certain environmental indicators.

Pollution, the forgotten face ofembodied energy

One of the main limitations of this methodology is thatit omits collateral environmental damage that may be linked to the product's life cycle.

As such, it does not take into account chemical pollution linked to the extraction of raw materials, their transformation or the end-of-life of products. This is the case, for example, with red mud generated during the aluminum manufacturing process.

The case of Coca-Cola is particularly eloquent. As we said, their initial analyses in the late 60s were part of the criteria that led them to favor the PET bottle, which consumes lessembodied energy than its glass ancestor. Unfortunately, this initiative also led them to become the world's leading source of plastic pollution, according to the latest reports from the NGO Break Free From Plastic.

However comprehensive and elaborate,embodied energy is not a sufficient indicator to measure the full environmental impact of a product. Other indicators will have to be added to measure the collateral damage generated during a product's life cycle.

A complex indicator to measure

Taking into account the entire life cycle of a product, building or service, embodied energy is difficult to measure. This is all the more true in the case of complex products made up of a wide variety of components.

The automotive industry is a prime example. Thousands of parts, from many different sources, made from materials that have been transformed many times.

Added to this complexity is the issue of product end-of-life. Which components of a complex product can be recycled or reused, and which will have to be destroyed? Does the end-of-life site have the necessary resources for recycling?

While it is possible to establish an average, the sheer number of criteria to be taken into account makes the results of this analysis relatively uncertain, and therefore requires a strict, standardized process as well as the willingness to act of all the players involved in a product's life cycle.

How to reduceembodied energy ?

As we mentioned,embodied energy represents on average ⅔ of a product's energy consumption. To reduce our negative impact on the environment, we therefore need to take this subject head on.

As the amount of energy consumed is strongly linked to the production of new products, we need to rethink our consumption patterns. Both in the quantity of products and in the way they are produced.

So we need to find a way of making this energy "profitable". Reducing the proportion ofembodied energy consumption in relation to the consumption of energy in use over the life of a product.

Extend product life

One of the first ways to reduce the amount of energy consumed is toincrease the lifespan of products. In fact, a product in working order will not (or should not) have to be replaced.

Increasing the life of products by combating programmed obsolescence or increasing their reparability can significantly reduce their environmental impact.

Then there's the question of whether it's better to replace a product that consumes a lot of embodied energy with a new, more energy-efficient product. The most complex products require a great deal ofembodied energy to manufacture, so replacing them with a less energy-intensive product is not always the best solution. Sometimes it's better to maximize the use of the current product.

Reduce energy consumption at source

The more a product is processed, the moreembodied energy it consumes. The further away a product comes from, the moreembodied energy it will consume.

By favoring raw materials, or at the very least less processed materials, we can considerably reduce the amount of energy consumed in the manufacture of a product. This is the case, for example, in the construction industry, where flax fibre insulation is far less damaging to the environment than polystyrene.

Similarly, using local products eliminates a large part of a product'sembodied energy , linked to the transportation of materials.

embodied energy and globalization

The analysis ofembodied energy has highlighted some of the mirages of decarbonization when studied within a restricted perimeter.

Over the last few decades, developed countries have tended to export their embodied energy to developing countries.

The relocation of whole swathes of European industry to Asia has led to a de facto relocation of our energy consumption, artificially reducing the official territorial emissions figures for European countries. China has thus become the world's leading exporter ofembodied energy.

Global differences in emissions linked to consumption and production in 2004 in Mt CO2/year
Global differences in emissions linked to consumption and production in 2004 in Mt CO2/year (red = net imports of emissions, blue = net exports of emissions) (Source: Imported emissions: the stowaway of world trade - Climate Action Network - Ademe - Citepa)

We therefore have a skewed view of our carbon emissions efforts. While our direct emissions are decreasing, our consumption ofembodied energy is tending to increase. This is due to our consumption patterns (more products, less quality), but also to the origin of the products we consume, with the transport of goods having a major impact on the amount of energy needed to obtain the product.

Conclusion

Whileembodied energy remains a valuable indicator for assessing the environmental impact of products and services, its use needs to be complemented by other tools enabling a more comprehensive assessment, taking into account chemical pollution and ecosystem degradation.

Reducing our dependence onembodied energy requires concerted action at all levels of society, from product design to our consumption habits, in order to promote sustainable, environmentally-friendly development. Last but not least, it is essential to take these actions on a global scale. A global, collaborative approach is needed to tackle these challenges and move towards a more responsible use of resources.

‍

Sources : 

HomeAcademy
This is some text inside of a div block.