Fernando Alcoforado*
This article aims to present the evolution of the use and production of energy from prehistory to the present time, as well as its probable future evolution towards the use of clean and renewable energy with the abandonment of fossil fuels. From prehistory to the 18th century, the use of renewable energy sources such as wood, wind and hydraulic energy predominated. From the 18th century to the contemporary era, fossil fuels predominated with coal and oil, but their use will probably end in the 21st century to avoid catastrophic global climate change resulting from their use in emitting greenhouse gases responsible for the global warming. With the end of the fossil fuels era will come the era of renewable energy sources when the use of hydroelectric energy, solar energy, wind energy, tidal energy, wave energy, geothermal energy, biomass energy and hydrogen energy will prevail.
Use and production of energy from prehistory to the 18th century
Energy is an essential input for human beings and for economic and social development. It can be argued that the most basic need of human beings is the energy to keep their bodies functioning. For a long time, in the dawn of humanity, muscle strength was the main source of energy used by man. At the beginning of human history, the domestication of animals provided the mechanical energy necessary for transport and agricultural production, etc. The discovery by human beings that they could control forms of energy that would be useful to them, such as fire, represented a very important milestone for humanity to be able to cook their food and heat up with the use of thermal energy. About 7 thousand years BC, in the Neolithic period, the use of fire began. A few millennia ago, hydropower from rivers and wind were used by humanity based on available science and technology. Around 12,000 years ago, the Agricultural Revolution marked the beginning of the use of animal traction, the power of winds and waterfalls in agricultural and livestock production.
During Antiquity, the use of wind in sailing navigation was essential for colonization and trade on the shores of the Mediterranean Sea, replacing rowing navigation that used human muscle strength. During the Roman Empire, from 31 BC to 410 AD, firewood was widely used for the production of weapons in the process of forging metals. This caused deforestation of much of Italy and the Iberian Peninsula. At the same time, far away from there, more specifically in China, great innovations in hydraulic technology were introduced, through the creation of water lifting devices and irrigation systems. Since the domain of fire until the advent of the 1st Industrial Revolution in the 18th century, there has been no great evolution in the way humanity uses energy. Changes in the global energy matrix, in terms of the diversity of sources and patterns of use, did not change much over the centuries until the 1st Industrial Revolution.
The use of coal from the 18th century on energy production
Only with the advent of the 1st Industrial Revolution, also called “the age of coal and iron”, which took place in England in 1786, the use and production of energy assume fundamental importance in the replacement of men and animals by machines. With the 1st Industrial Revolution and the consequent industrialization process, the need for energy increased and new primary sources, with greater energy density, were introduced. The use of coal as an energy source marked the end of the era of renewable energy represented by the use of wood and the meager hydraulic and wind farms used since the dawn of humanity to start the non-renewable energy era, the era of fossil fuels with the use of coal and the invention of steam engines.
A steam engine has a boiler, which, with the heat from burning fuel, causes the water to turn into steam, with the purpose of transforming the hot energy that is released by burning fuel, coal. The adoption of the steam engine was slow, taking a century after James Watt’s patent (1769) was used to transform industrial production and land transport with the advent of the railroad and its use in long-distance maritime transport with steam vessels. The replacement of charcoal by coke in iron smelting was one of the “greatest technical innovations of the modern era, as it ended the unsustainable use of wood in England and skyrocketed iron production. In addition, coal laid the foundation for the modern steel industry and paved the way for the advent of the key metal of industrialization, iron.
The use of oil from the 19th century onwards in energy production
From 1860 onwards, in England, new transformations in the industry emerged. This phase was called the 2nd Industrial Revolution which became known as the “era of steel and electricity”. With the 2nd Industrial Revolution, which lasted until the first half of the 20th century, new fuels with greater energy power were needed, with petroleum being the fuel that brought these properties together. Thus began a new phase in the use of liquid fuels that continues to this day. Initially, petroleum was used only to obtain kerosene and lubricating oils. At that time, the gasoline generated during the distillation of oil was thrown away in rivers or burned. It was sometimes mixed with kerosene to produce a dangerous explosive. Among the inventions that emerged during the 2nd Industrial Revolution are the Bessemer process of transforming iron into steel, which allowed the production of steel on a large scale, the dynamo that allowed the replacement of steam by electricity and the internal combustion engine that allowed the large-scale use of oil creating conditions for the use of its derivatives in the automobile and, later, in trucks and planes.
The use of gasoline as a fuel for motor vehicles only began after the invention of internal combustion engines and large-scale car production. The automobile became viable with the invention of the internal combustion engine and the discovery that one could use the petroleum derivative, gasoline, as fuel, which took place from 1876 onwards. Nikolaus August Otto, German engineer and inventor, invented it and built the first four-stroke internal combustion engine and determined the theoretical cycle under which the combustion engine works, the well-known Otto cycle. Thereafter, the demand for petroleum products, especially gasoline, rose sharply in industrialized countries. The oil until then only used to obtain kerosene became a source of obtaining gasoline. A few decades later, this same trend turned diesel into a fuel used in jeeps and trucks, and fuel oil that was widely used in industry after World War II.
The use of electricity from the 19th century on energy production
The 2nd Industrial Revolution was the continuation of the process of revolution in industry, through the improvement of techniques, the creation of machines and new means of production. Advances in scientific and technological knowledge enabled the use of electricity and the invention of electrical machines in the 19th century, together with the introduction of automotive vehicles, which laid the foundation for the introduction of the modern consumer society, characterized by an energy intensity never seen before in the history of humanity. It was in 1913 in the United States, with the automobile industry as its flagship, that the Second Industrial Revolution was consolidated. With the 2nd Industrial Revolution, electricity emerged as a combined effort of several engineers and scientists, starting with Michael Faraday’s discovery of electromagnetic induction. This culminated in the work of Thomas Edison, who not only designed the first light bulb, but also built an electricity generating plant and a direct current electrical system in 1880 to power customers in lower Manhattan, New York.
Later, in the last two decades of the nineteenth century, the famous “war of electric currents” took place between alternating current advocated by Nikola Tesla and George Westinghouse and direct current advocated by Thomas Edison. The difference between direct current and alternating current is that, while in direct current, electrons move in only one direction, alternating current has electrons that change their direction constantly. If electrons move in only one direction, this current is called continuous. If electrons change direction constantly, it is alternating current. For the distribution of electricity, alternating electrical current is significantly more practical than direct current, as it is much easier to change the electrical voltage into alternating current than the voltage of direct current.
Based on a work with rotational magnetic fields, Nikola Tesla developed a system for generating, transmitting and using electrical energy from alternating current. Tesla has partnered with George Westinghouse to market this system. The “war of electrical currents” ended up favoring alternating current because it has the advantage of being able to easily lower or increase its electrical voltage through transformers, and high power transmission is more economical, as it offers less energy loss. The electrical systems deployed in the world started to be based on it. Today, alternating current is the norm for electrical energy systems that produce electricity using conventional and nuclear hydroelectric and thermoelectric plants, among others.
The use of nuclear energy from the 20th century onwards in the production of electrical energy
The operation of a nuclear plant in the generation of electricity consists of using the nuclear reactor (the main part of the plant) to simply boil water whose steam is used by a thermodynamic cycle to move an alternator and produce electricity. Nuclear energy is obtained from the fission of the nucleus of the enriched uranium atom, releasing a large amount of energy. The transformation of nuclear energy into electrical energy can happen in a controlled manner in a nuclear reactor through the nuclear fission of uranium as the main civil application of nuclear energy. Electric power was first generated by a nuclear reactor on September 3, 1948 by the X-10 Graphite Reactor in Oak Ridge, Tennessee, United States by turning on an electric light. Today, the United States is the country with the highest number of nuclear power plants, totaling 104, representing 18% of the country’s energy matrix. France is at the top of the countries with the greatest dependence on this type of energy, using 80% of nuclear energy in its energy matrix.
The main advantage of nuclear energy is that it makes it possible to avoid using fossil fuels such as oil and coal in the production of electricity, which has come to be defended even by some ecologists because it does not generate greenhouse gases. These ecologists advocate a radical shift towards nuclear energy as a way to combat global warming resulting from the emission of greenhouse gases from fossil fuels, especially oil. Compared to hydroelectric generation, the use of nuclear energy has the advantage of not requiring the flooding of large areas for the formation of reservoir lakes, thus avoiding the loss of natural reserve areas or agricultural land, as well as the removal of entire communities in the areas that are flooded. However, nuclear power plants have the disadvantage related to the final disposal of their waste (atomic waste) that has not been resolved to date and the impossibility of avoiding accidents such as those that occurred in Chernobyl in 1986 and in Fukushima in 2011 which, when they occurred, took on catastrophic dimensions. .
Fossil fuels and global climate change
There is no doubt that human activities on Earth cause changes in the environment in which we live. Many of these environmental impacts come from the generation, handling and use of energy with the use of fossil fuels. The main reason for the existence of these environmental impacts lies in the fact that the world consumption of primary energy from non-renewable sources (oil, coal, natural gas and nuclear) corresponds to approximately 88% of the total, with only 12% of renewable sources. This huge dependence on non-renewable energy sources has resulted, in addition to the permanent concern with the possibility of depletion of these sources, the emission of large amounts of carbon dioxide (CO2) and other greenhouse gases into the atmosphere that set a record in 2013 having been on the order of 36.3 billion tons, approximately 3.9 times the amount issued in 1960 (9.3 billion tons).
Everything suggests that, if the current trend in energy consumption is maintained, the share of fossil fuels (oil, coal and natural gas) in the world energy matrix will reach 80% in 2030. Oil has a dominant position among the sources of energy used. Oil, coal and natural gas are, in order, the most used energy sources today in the world’s final energy consumption. The industrialized countries of the OECD (Organization for Economic Cooperation and Development) are the biggest energy consumers, followed by China, Russia and other countries in Asia. According to the International Energy Agency, oil and coal are the main responsible for the emission of CO2 into the atmosphere, whose biggest emitters are the industrialized countries of the OECD [See article AIE: mundo se encaminha para futuro energético insustentável (IEA: world moves towards an unsustainable energy future) published on the website <http://g1.globo.com/mundo/noticia/2011/11/aie-diz-que-mundo-se-encaminha-para-futuro-energetico-insustentavel.html>). If the current trend is maintained, it is very likely that by 2025 the world will be using 75% more energy and that most of it will be supplied by oil, coal, natural gas and nuclear energy. This is the likely energy scenario for the next 30 years, if the current global energy matrix is maintained.
The International Energy Agency (IEA) warned that “the world will move towards an unsustainable energy future” if governments do not adopt “urgent measures” to optimize available resources. For the IEA, by 2035 a global investment of US$ 38 trillion in energy infrastructure would be needed – two thirds in countries outside the Organization for Economic Cooperation and Development (OECD) – to meet the growing demand, 90% to supply emerging countries like China and India. Regardless of the various solutions that may be adopted to eliminate or mitigate the causes of the greenhouse effect, the most important action is, without a doubt, the adoption of measures that contribute to the elimination or reduction of the consumption of fossil fuels in energy production, as well as for its more efficient use in transport, industry, agriculture and cities (homes and commerce), given that the use and production of energy are responsible for 57% of the greenhouse gases emitted by human activity (Lashof, DA & Tirpak, DAorgs. Policy options for stabilizing global climate, Washington, DC, Environmental Protection Agency, 1989). In this sense, it is essential to implement a sustainable energy system.
The future sustainable energy system
In a sustainable energy system, the global energy matrix should only rely on clean energy sources (hydroelectric, solar, wind, hydrogen, geothermal, tidal, wave and biomass), and therefore should not rely on the use of fossil fuels (oil, coal and natural gas). Until this condition is reached, the world energy matrix should go through a transition in which renewable and non-renewable energy sources coexist, such as the proposal by the Worldwatch Institute, which advocates halving the world production of oil and 90% of coal, while renewable energy sources should grow almost 4 times. By the year 2030, renewable energies should account for 70% of the planet’s total energy production. To optimize the energy resources available on the planet, it is necessary to implement a sustainable energy system on a global scale. The technologies are already available to initiate this historic energy transition that will only occur with fundamental changes in energy policy in the vast majority of countries [ALCOFORADO, Fernando. Energia no mundo e no Brasil (Energy in the world and in Brazil). Curitiba: Editora CRV, 2015. Page 31].
According to the Worldwatch Institute, the first step in changing energy policy in the world is to redirect a large number of government policies in countries so that they are aimed at achieving the central goals of energy efficiency and reducing the use of fossil fuels. For example: rewarding the acquisition of efficient motor vehicles and electric vehicles with reduced taxes on them, encouraging high-capacity mass transport alternatives on rails such as subways and trams to replace the automobile, implementing railroads to replace the use of trucks in freight transport, restructure industries to make use of clean and renewable energies and raise taxes on fossil fuels. A sustainable energy system will only be possible if, in addition to abandoning fossil fuels, energy efficiency is also greatly improved. With the sustainable energy system, it is very possible that natural gas will become, among fossil fuels, the only one of these energy resources to be used in the future. Nuclear energy will not be an important source of energy in a truly sustainable energy system. This is largely due to the accidents at Chernobyl in the former Soviet Union and Fukushima in Japan.
Regardless of the various solutions that may be adopted to eliminate or mitigate the causes of the greenhouse effect, the most important is undoubtedly the adoption, in the transition phase, of measures that contribute to the elimination or reduction of the consumption of fossil fuels in the production of energy, as well as for its more efficient use in transport, industry, agriculture and cities (homes and commerce), given that the use and production of energy are responsible for the emission of 57% of the greenhouse gases emitted by the human activity. In this sense, it is essential to implement a sustainable energy system.
Conclusions
For these reasons, humanity is currently facing the urgent need to replace fossil fuels (coal, oil and natural gas) with clean energy sources to avoid the catastrophic climate change that is admitted with the maintenance of the current energy policy, as well how to adopt energy efficiency or energy saving measures to reduce dependence on fossil fuels. Clean energy refers to any energy source that does not emit polluting substances. This is the most basic and succinct definition of clean energy. Its production and consumption are important for protecting the environment and for improving people’s quality of life.
The clean energy sources to be used preferably are (hydroeletric, solar, wind, hydrogen, geothermal, tidal, wave and biomass). Exceptionally, nuclear energy could be used as a source of energy, which would have restrictions due to the risks it represents, and natural gas, as it is the fossil fuel that is less aggressive to the environment. Clean energy sources are already a reality around the world. The future of the energy sector around the world will necessarily mean the use of clean energy sources. Clean energy is a concrete alternative to face environmental degradation and the misuse of the planet’s natural resources. The use of clean energy is, without a doubt, the rational way to guarantee the sustainability of planet Earth for current and future generations.
The transition from the current energy matrix based on fossil fuels to one that contemplates the adoption of an energy matrix based on clean energy requires the optimization of energy resources available on the planet, with world oil production being reduced by half and coal by 90% , while that of renewable energy sources would grow almost 4 times. Progressively, the world energy matrix would evolve to have in its composition the predominance of clean and renewable energy.
* Fernando Alcoforado, 81, awarded the medal of Engineering Merit of the CONFEA / CREA System, member of the Bahia Academy of Education, engineer and doctor in Territorial Planning and Regional Development by the University of Barcelona, university professor and consultant in the areas of strategic planning, business planning, regional planning and planning of energy systems, is author of the books Globalização (Editora Nobel, São Paulo, 1997), De Collor a FHC- O Brasil e a Nova (Des)ordem Mundial (Editora Nobel, São Paulo, 1998), Um Projeto para o Brasil (Editora Nobel, São Paulo, 2000), Os condicionantes do desenvolvimento do Estado da Bahia (Tese de doutorado. Universidade de Barcelona,http://www.tesisenred.net/handle/10803/1944, 2003), Globalização e Desenvolvimento (Editora Nobel, São Paulo, 2006), Bahia- Desenvolvimento do Século XVI ao Século XX e Objetivos Estratégicos na Era Contemporânea (EGBA, Salvador, 2008), The Necessary Conditions of the Economic and Social Development- The Case of the State of Bahia (VDM Verlag Dr. Müller Aktiengesellschaft & Co. KG, Saarbrücken, Germany, 2010), Aquecimento Global e Catástrofe Planetária (Viena- Editora e Gráfica, Santa Cruz do Rio Pardo, São Paulo, 2010), Amazônia Sustentável- Para o progresso do Brasil e combate ao aquecimento global (Viena- Editora e Gráfica, Santa Cruz do Rio Pardo, São Paulo, 2011), Os Fatores Condicionantes do Desenvolvimento Econômico e Social (Editora CRV, Curitiba, 2012), Energia no Mundo e no Brasil- Energia e Mudança Climática Catastrófica no Século XXI (Editora CRV, Curitiba, 2015), As Grandes Revoluções Científicas, Econômicas e Sociais que Mudaram o Mundo (Editora CRV, Curitiba, 2016), A Invenção de um novo Brasil (Editora CRV, Curitiba, 2017), Esquerda x Direita e a sua convergência (Associação Baiana de Imprensa, Salvador, 2018), Como inventar o futuro para mudar o mundo (Editora CRV, Curitiba, 2019) and A humanidade ameaçada e as estratégias para sua sobrevivência (Editora Dialética, São Paulo, 2021) .
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