The energy system

Energy Energy knowledge

All organisms need energy to live. Energy is connected to all human activities: whenever we think or move, we use the energy that is stored in our body and all the objects that we use or that surround us need energy to work or needed energy when they were built. Energy illuminates us and warms our houses, allows us to move, feeds the tools we use to produce food, and so on.

Energy has by now become an inseparable partner of human beings, who use it at any time every day in all their activities. To ensure the possibility of benefiting from that resource in a simple, stable and constant way, mankind had to conduct studies and research for a long time, and only during the last decades of the 19th century did many nations, but not all, succeed in developing “energy systems” ensuring the quality and quantity of energy necessary for development.

With the term “energy system” we usually indicate the set of processes involving production, transformation, transport and distribution of energy sources. Energy systems are usually extremely complex, and require skills from all fields of science in order to build and manage them. In fact, just as it is simple to use the energy that is made available to us at home (we press a switch and the light turns on) so is it difficult and complex to produce that energy and bring it right into our homes.

Distribution and transformation

The first is that the production of the currently most exploited energy sources (fossil fuels) is concentrated under the surface of few countries, often far from the consuming countries. Therefore finding and extracting the energy source and developing ad hoc agreements between producing and consuming countries is necessary to ensure a stable and lasting provision of fossil fuels to the latter. Finally, the physical transportation of the energy sources from the producing to the consuming countries is to be taken care of.

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Energy: yesterday and today

The history of mankind has always been characterized by the search for new sources of energy: to ensure survival at first and then to improve the standard of living. At the beginning energy meant manpower, often supplied by slaves and beasts of burden; later the energy of wind (windmills) and water (water mill wheels and similar machines) started to be exploited.

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The importance of energy in modern society led man not only to create complex “energy systems”, but also to try and measure how much energy he uses each year and understand which source he gets it from and from which Country he imports it from.

These problems have been solved by using adequate energy measurement units and a scheme representing the energy flows that enter a country and how energy is used in the different sectors along the year: the National Energy Balance.

The national energy balance

Like any other balance, the energy balance collects information on energy input and output. The national energy balance is the most famous one and is a collection of information on how energy is produced and used within a Country during the year.

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Information obtained from the NEB

The National Energy Balance is drafted every year. Thus comparing and contrasting the energy consumption is possible over the years by analyzing the different origin (whether imported or home produced), the different composition (which energy sources were exploited) and the development of national consumption (whether increasing or decreasing) of energy.

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Final use of energy

How does a country use the annual primary energy sources available? The answer is provided in the second part of the households and enterprises (of course enterprises producing electric energy to be destined to final uses are excluded).

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Energy is an indispensable element to guarantee the well-being and development of the planet. Without a regular supply of energy, cities, industries, transportation and infrastructures would come to a halt. Moreover, the growth of the world economy and consumption in the 20th century, has been based mainly on exploiting fossil fuels: first coal, then petroleum and natural gas. These sources of energy, however, are not renewable and are destined, in the future, to become depleted. Furthermore, these sources of energy emit polluting substances during combustion, even if the amounts vary greatly, depending on which fuel is used.

Impacts and protection of the air

Among the most important substances are: carbon oxides (COx), sulphur oxides (SOx), nitrogen oxides NOx), volatile organic compounds (VOC) and total particulate solids (TPS). These pollutants can be harmful for human health and for the environment if they exceed determined concentrations in the air.

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Challenges of the renewable energy sources

80% of the world energy is obtained from fossil fuels which are precious sources that, however, are not renewable. And it is for this reason that it has become necessary to develop and increase the renewable energies, but to do so, a few rather difficult issues must be overcome. First of all it is necessary to successfully produce energy from the renewable sources so that they are economic and competitive when compared to the traditional energy sources.

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The expression ‘energy transition’ refers to the move towards sustainable economies, through the use of renewable energy, the adoption of energy-saving techniques and sustainable development. Energy transition is a process that has accompanied the human race from the very beginning and has enabled the development and progress of human civilisation.

What does ‘energy transition’ mean?

There are two fundamental elements that characterise an energy transition. The first is that it is a complex and time-consuming process, as it involves structural changes in the way energy is produced and used. The second concerns the impact of the energy transition on economic development, quality of life, social organisation and the environment.

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A little history

Energy transitions have always accompanied human history. This has involved a continuous process and the time limits between transitions are not always easy to identify. For this reason, the classification by Vaclav Smil, a scholar of energy history who identified four epoch-making energy transitions, is given here.

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The origin of the energy transition: mega-trends

Development of an energy system is driven by major forces of growth and change, which modify and shape the entire social organisation and production system, and direct the collective consciousness and the main choices of entrepreneurs, consumers and policy-makers. These forces are referred to as mega-trends. Indeed, mega-trends are what drive the new energy transition and its timing.

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Sustainable energy for all, the challenge of the century

Of the mega-trends driving the energy transition today, three stand out in terms of relevance and impact:

Climate change mitigation
Access to energy and the fight against energy poverty
World population growth

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