Why Energy Efficiency is an important issue today?

World Energy Consumption Evolution over the past century

Vincent BRYANT

For about a century, the world population has been multiplied by 12. We are 12 times as many today as at the end of the XIXth century. Since 1879, when was the electric bulb was created, the world energy consumption has been multiplied by more than 50.

Alongside the increase of the world population, we can indeed notice that the energy needs per person also increase greatly, despite the innovations and the technological improvements from which the population benefits. Indeed, the technical yields were generally strongly improved during the past century, but these efforts have been completely compensated by two effects:

  • the park effect (always more goods consumed, increasing thus the penetration rate of the goods, for example in 50 years the level of refrigerators equipment has strongly increased)
  • and the multiplier effect of the uses (always more additional uses becoming real by addition of functionalities, for example mobile phones also have a camera function).

Therefore, innovation will be necessary again to avoid a scenario where energy consumptions and GreenHouse Gas emissions wouldn’t stop increasing.

We note in parallel that 80% of the world consumed energy is of fossil origin (oil, natural gas, coal) used directly or to produce electricity. At this level, it appears difficult to subtract ourselves from our dependence towards these energies in a few years, substituting them only for example by renewable energies (which, other than wood, only represent today a small fraction of the world consumption).

In fact, the fossil fuels have two major downsides:

  1. They only exist in a limited quantity on Earth and aren’t renewable on a human ladder of time.
  2. Their use (by combustion among other ways) emits greenhouse gas, and more particularly CO2.

Experts agree to say that the use by man of fossil fuels modify our climate. We are facing here a real threat for the climatic system and for our future life conditions. Climate change, influenced by this increase of GreenHouse Gas levels, generates many consequences for our societies (global warming, sea level rising, extreme phenomena, rising and intensification, etc.).

Today, renewable energies (outside hydraulic and biomass) only represent a very small part of the world energy mix. Even if they present a real potential, these energies are nevertheless insufficient to replace non renewable energies in a few decades. It appears therefore necessary, firstly, to reduce the energy consumption and to increase the Energy Efficiency.

In a forthcoming post, we’ll see the reasons that could push individuals, companies and local authorities to implement Energy Efficiency solutions across different countries.


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