Feature Report: Energy Efficiency

2 items of content in this feature report

Tell me more


Energy Efficiency and Energy Intensity Versus Energy Conservation

The goal of energy efficiency is to be less wasteful in using the energy required by human activities. This push for improved performance has gone global in the last few decades, as it provides a way to reduce energy bills and continue meeting the needs of the world's population. However, progress has been held back by issues of competitiveness, cost and capital expenditure, as well as by the recession.  

Less energy-intensive urban lighting, using solar-powered solutions, for example, improves energy efficiency without sacrificing performance. ©THINKSTOCK

Energy Efficiency, Energy Conservation and Energy Intensity

Energy efficiencyIn economic terms, energy efficiency refers to the efforts made to reduce the energy consumption of a system... refers to the efforts made to reduce the energy consumption of a system, such as a building, factory or vehicle, while having it perform the same functions. It is measured by the ratioIn mathematics, the relationship between two numbers (the ratio of x to y is equal to x/y). Often expressed as a percentage... of the energy used to perform the actual function and the total energy consumed by the system. The goal is to optimize energy use by minimizing losses.

The notion of "performing the same functions" is important: making a system more energy efficient means saving energy without sacrificing performance. Globally, it means using less energy without letting growth stall. The concept of energy efficiency can apply equally to a factory or to an entire country's economy. In the latter case, the term used is energy intensity, meaning the additional amount of energy required to increase the country's GDP.


1.2 billion people worldwide do not have access to electricity.

"Energy efficiency" is not synonymous with "energy conservation," even though both save energy. Energy conservation, as defined by the French NGO negaWatt,1 "Consists of rethinking our needs and then shaping individual behavior and collective organization to change the various ways we use energy, with the goal of focusing on the most useful, curbing the most extravagant and eliminating the most harmful." An example of energy conservation is turning the thermostat down one or two degrees in a heated room. An example of energy efficiency, on the other hand, would be to install thermal insulation or a more efficient boiler in the building, to heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... the room to the same temperature using less energy.

Emerging Countries' Needs

Some 2.8 billion individuals on the planet still use wood to cook their meals and heat their homes and 1.2 billion still lack access to electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor....2 What's more, the global population is growing and is expected to rise from 7 billion people today to 9 billion (8 to 11 according to demographers) in 2050. Energy will be required to meet their needs.

Global energy demand will grow by one-third between 2010 and 2035 and 90% of that growth will take place outside the industrialized countries of the Organization for Economic Cooperation and Development (OECDFounded in 1960, the OECD promotes policies that will improve the economic and social well-being of people around the world...), with China and India accounting for more than half of the increase.3

80% of the world's countries have set quantitative energy efficiency targets.


Energy efficiency has made great strides in every region of the world. In the last 30 years, most countries have sharply reduced their total primary energyAll energy sources that have not undergone any conversion process and remain in their natural state.. use per unit of gross domestic product (GDP) growth per capita, at purchasing powerIn physics, power is the amount of energy supplied by a system per unit time. In simpler terms, power can be viewed as energy output... parity (PPP). Much of this desirable decline in "energy intensity" is driven by improved energy efficiency in the three major consuming sectors:

Uneven Performance and a Recent Slowdown

Western Europe, Japan and Hong Kong rank among the regions with the lowest energy intensity. Energy intensity in the Commonwealth of Independent States (the former Soviet bloc) is almost three times higher than the European average, while the figures in China, Africa and the Middle East are almost twice as high. North America (U.S. and Canada) has an energy intensity nearly 1.5 times that of Europe.

Energy efficiency has become a global priority. It benefits individuals by enhancing their purchasing power, companies by cutting their costs and national governments by trimming their energy bills, while helping to further the necessary reductions in carbon emissions to combat global warmingGlobal warming, also called planetary warming or climate change....

As a result, primary energy intensity has fallen 1.3% worldwide since 1990. Some 80% of the countries studied by the French Environment and Energy Management Agency (ADEME)4 have set quantitative targets for energy efficiency, up from 40% in 2006.

But this positive trend has slowed since 2008, especially in India and China, due mainly to the global economic recession, which has shifted the focus back to supporting growth. New public incentives, technological innovations and improved international coordination are needed.


Sources :

(1) French NGO negaWatt

(2) World Bank - Global Tracking Framework Report

(3) World Energy Outlook – IEA