Article | REF: BE8517 V2

Grey energy

Author: Christian NGÔ

Publication date: July 10, 2024

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!


Overview

Français

Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.

Read the article

AUTHOR

  • Christian NGÔ: Edmonium

 INTRODUCTION

This article introduces and sensitizes the reader to the problem of grey energy or embodied energy in the objects and processes used every day by private individuals, industry and services. Users are sensitive to the energy they consume to operate an object, such as their car or electric heater, but much less so to the energy that went into making it, maintaining it (although they often pay for this maintenance) and disposing of it once it has become unusable or useless. This grey energy is also associated with various environmental impacts such as the emission of CO 2 and pollutants, the creation of waste or the depletion of natural resources.

Defining energy consumption for the use of an object or good is no easy task. This quantity of energy, known as operational energy, is that which is accounted for and paid for directly or indirectly by the user. Defining the amount of grey energy associated with an object, good or service is even more difficult. Consumers often have no idea of the value of this hidden energy. And yet, the amount of energy required to manufacture an object can sometimes be considerable compared to the energy it can supply or consume during use. For example, it takes around fifty times more energy to make an alkaline battery than the amount of electricity it supplies when in use.

Primary energy corresponds to energy before transformation. This is the case, for example, with crude oil, coal or water from a dam. Secondary energy is obtained after transformation: petrol or diesel from oil, charcoal from wood, electricity from natural gas, etc. Final energy is that used by the consumer, such as electricity or heating oil. Finally, useful energy is that which is actually used for the required purpose. Between final energy, which the consumer pays for, and primary energy, which is used to produce it, significant losses occur. In the case of French electricity, for example, it takes an average of 2.6 kWh of primary energy to produce 1 kWh of electricity consumed by the user.

You do not have access to this resource.

Exclusive to subscribers. 97% yet to be discovered!

You do not have access to this resource.
Click here to request your free trial access!

Already subscribed? Log in!


The Ultimate Scientific and Technical Reference

A Comprehensive Knowledge Base, with over 1,200 authors and 100 scientific advisors
+ More than 10,000 articles and 1,000 how-to sheets, over 800 new or updated articles every year
From design to prototyping, right through to industrialization, the reference for securing the development of your industrial projects

This article is included in

Energy resources and storage

This offer includes:

Knowledge Base

Updated and enriched with articles validated by our scientific committees

Services

A set of exclusive tools to complement the resources

Practical Path

Operational and didactic, to guarantee the acquisition of transversal skills

Doc & Quiz

Interactive articles with quizzes, for constructive reading

Subscribe now!

Ongoing reading
Grey energy