Fernando Alcoforado*
Abstract: This article aims to present how the evolution of energy consumption and production occurred from prehistory to current times, as well as proposing the future of energy required for the world.
Keywords: Use and production of energy throughout history. Energy future required for the world.
1. Introduction
This article aims to present how the evolution of energy consumption and production occurred from prehistory to current times, as well as proposing the future of energy required for the world. From prehistoric times until the 18th century, the use of renewable energy sources such as wood, wind and hydraulic energy predominated. From the 18th century until the contemporary era, fossil fuels predominated with coal and oil, but their use will probably end from the 21st century onwards to avoid catastrophic global climate change resulting from their use by emitting greenhouse gases responsible for the global warming. With the end of the era of fossil fuels 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.
2. Use and production of energy from prehistory to the 18th century [1][2]
For a long time, in the early days of humanity, muscular strength was the main source of energy used by man. In the early history of humanity, 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, using thermal energy, to be able to cook their food and keep warm. Around 7 thousand years ago BC, in the Neolithic period, the use of fire began. A few millennia ago, hydraulic energy from rivers and wind energy were used by humanity based on available technology. Around 12 thousand years ago, the Agricultural Revolution marked the beginning of the use of animal traction, wind power 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 muscular strength. During the Roman Empire, from 31 BC to 410 AD, firewood was widely used to produce weapons in the process of forging metals. This caused the deforestation of much of Italy and the Iberian Peninsula. At the same time, very far away, more specifically in China, great innovations in hydraulic technology were introduced, through the creation of water lifting devices and irrigation systems. From the domination of fire to the advent of the 1st Industrial Revolution in the 18th century, there was no major evolution in the way humanity used energy. Changes in the global energy matrix, in terms of the diversity of sources and usage patterns, did not change much over the centuries until the 1st Industrial Revolution.
3. The use of mineral coal from the 18th century onwards in energy production [1][2]
Only with the advent of the 1st Industrial Revolution, also called the “age of coal and iron”, which occurred in England in 1786, did the use and production of energy assume fundamental importance in replacing men and animals with machines. With the 1st Industrial Revolution and the resulting industrialization process, the need for energy increased and new primary sources, with greater energy density, were introduced. The use of mineral coal as a source of energy marked the end of the era of renewable energy represented by the use of wood and the scarce hydraulic and wind power used since the beginning of humanity to begin the non-renewable era of energy, the era of fuels fossils with the use of mineral coal and the invention of steam engines.
A steam engine has a boiler that, with the heat from burning fuel, causes water to transform 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 railway and its use in long-distance maritime transport with steam vessels. . The replacement of charcoal with 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 dramatically increased iron production. Furthermore, coal laid the basis for the modern steel industry and paved the way for the advent of the key metal of industrialization, iron.
4. The use of oil from the 19th century onwards in energy production [1][2]
From 1860 onwards, in England, new transformations emerged in the industry. This phase was called the 2nd Industrial Revolution, which became known as the “age 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 oil being the fuel that brought together these properties. 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, gasoline generated during the distillation of oil was thrown away into rivers or burned. Sometimes it was mixed with kerosene to produce a dangerous explosive. Among the inventions that emerged during the 2nd Industrial Revolution are the Bessemer process for 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 use of oil on a large scale creating conditions for the use of its derivatives in automobiles and, later, in trucks and airplanes.
The use of gasoline as a fuel for motor vehicles only began after the invention of internal combustion engines and the large-scale production of automobiles. The automobile became viable with the invention of the internal combustion engine and the discovery that the petroleum derivative, gasoline, could be used as fuel, which occurred in 1876. Nikolaus August Otto, a German engineer and inventor, was the one who invented and built the first four-stroke internal combustion engine and determined the theoretical cycle under which the explosion engine works, the well-known Otto cycle. From then on, the demand for petroleum derivatives, especially gasoline, increased dramatically in industrialized countries. Oil, previously only used to obtain kerosene, became the source of gasoline. A few decades later, this same trend transformed diesel into a fuel used in jeeps and trucks and fuel oil widely used in industry after the Second World War.
5. The use of electricity from the 19th century onwards in energy production [1][2]
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 foundations 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 electric light bulb, but also built an electricity generating plant and direct current electrical system in 1880 to provide power to customers in lower Manhattan in New York.
Later, in the last two decades of the 19th century, the famous “war of electrical currents” took place between the alternating current defended by Nikola Tesla and George Westinghouse and the direct current defended by Thomas Edison. The difference between direct electrical current and alternating current is that, while in direct current the electrons move in a single direction, alternating current has electrons that constantly vary their direction. If the electrons move in only one direction, this current is called direct. If the electrons constantly change direction, it is alternating current. For distributing electricity, alternating electrical current is significantly more practical than direct current, since it is much easier to change the electrical voltage in alternating current than the voltage in direct current.
Based on work with rotational magnetic fields, Nikola Tesla developed a system for generating, transmitting and using electrical energy from alternating current. Tesla collaborated with George Westinghouse to commercialize this system. The “war of electric 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. Electrical systems implemented around the world are now based on alternating current. Today, alternating current is the norm for electrical power systems that produce electricity using conventional and nuclear hydroelectric and thermoelectric plants, among others.
6. The use of nuclear energy from the 20th century onwards in the production of electrical energy [1][2]
The operation of a nuclear power plant to generate electricity consists of using the nuclear reactor (main part of the plant) to simply boil water whose vapor is used by a thermodynamic cycle to move an alternator and produce electrical energy. Nuclear energy is obtained from the fission of the nucleus of an enriched uranium atom, releasing a large amount of energy. The transformation of nuclear energy into electrical energy has been carried out in a controlled manner in a nuclear reactor through the nuclear fission of uranium as the main civil application of nuclear energy. Electrical 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 lighting an electric lamp. Today, the United States is the country with the largest number of nuclear 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 turn toward 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 to form reservoir lakes, thus avoiding the loss of areas of natural reserves or agricultural land, as well as the removal of entire communities in areas that are flooded. However, nuclear plants have a 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 assumed catastrophic dimensions. .
7. 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 using fossil fuels. The main reason for the existence of these environmental impacts lies in the fact that global consumption of primary energy from non-renewable sources (oil, coal, natural gas and nuclear) corresponds to approximately 88% of the total, with only 12% coming from renewable sources. This enormous dependence on non-renewable energy sources has led, in addition to the permanent concern about the possibility of depletion of these sources, to the emission of large quantities of carbon dioxide (CO2) and other greenhouse gases into the atmosphere, which reached a record in 2013, having was on the order of 36.3 billion tons, approximately 3.9 times the amount emitted 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 global 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 global final energy consumption. The industrialized countries of the OECD (Organization for Economic Co-operation and Development) are the largest consumers of energy, followed by China, Russia and other countries in Asia. According to the International Energy Agency, oil and coal are the biggest responsible for CO2 emissions into the atmosphere, the biggest emitters of which are the industrialized countries of the OECD.
The International Energy Agency (IEA) has warned that “the world will be heading towards an unsustainable energy future” if governments do not take “urgent measures” to optimize available resources. For the IEA, by 2035 global investment of US$38 trillion would be needed in energy infrastructure – two thirds in countries outside the Organization for Economic Co-operation and Development (OECD) – to meet growing demand, 90% to supply emerging countries, such as 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 well as for its more efficient use in transport, industry, agriculture and cities (residences and commerce), given that the use and production of energy are responsible for 57% of greenhouse gases emitted by human activity [8]. In this sense, the implementation of a sustainable energy system is essential.
In a sustainable energy system, the global energy matrix should only rely on clean and renewable energy sources (hydroelectric, solar, wind, hydrogen, geothermal, tidal, wave and biomass), and should therefore not rely on the use fossil fuels (oil, coal and natural gas) [7]. Exceptionally, it could use natural gas, which is the least polluting fossil fuel, and nuclear plants because they are sources of clean energy in the energy transition phase. Until the ideal situation is reached, the global energy matrix should go through a transition phase in which renewable and non-renewable energy sources coexist. Technologies are already available to begin this historic energy transition that will only occur with fundamental changes in energy policy in the vast majority of countries [3].
8. The energy future required for the world
The transition from the current energy matrix based on fossil fuels to the energy matrix based on clean and renewable energy requires, as a first step, the adoption of changes in energy policy in the world, which consists of redirecting a large number of countries’ government policies so that intended to achieve the central objectives of energy efficiency and reducing the use of fossil fuels [6]. 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 VLT to replace automobiles, implementing railways to replace the use of trucks in long-distance freight transport, restructure industries to make use of clean and renewable energy and raise taxes on fossil fuels.
The clean and renewable energy sources to be used preferably are hydroelectric, solar, wind, hydrogen, geothermal, tidal, wave and biomass. Exceptionally, nuclear energy may be used as an energy source, which would have restrictions due to the risks it represents, and natural gas, as it is the least aggressive fossil fuel to the environment. Clean and renewable 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 and renewable energy sources. Clean and renewable energy is a concrete alternative to combat environmental degradation and the misuse of the planet’s natural resources. The use of clean and renewable energy is, without a doubt, the rational way to guarantee the sustainability of planet Earth for current and future generations [3].
The use of solar energy and other renewable energies will cause changes of great magnitude across the planet, notably the creation of completely new industries, the development of new transport systems and the modification of agriculture and cities. The great challenge facing us today is to continue advancing science and technology in order to efficiently harness energy and economically use renewable resources. This is the alternative energy scenario that could replace the scenario in which the use of non-renewable energy sources prevails, thus avoiding compromising the global environment. This means that profound changes in global energy policy must be put into practice to reduce the consumption of fossil fuels, which account for 80% of global energy supplies [6].
The direct conversion of solar energy into electricity and heat is likely to be the cornerstone of a sustainable global energy system. Solar energy is not only available in large quantities, it is also more widely distributed than any other energy source. Within a few decades, the Sun will be able to be used to heat most of the water needed, and new buildings will be able to take advantage of natural heating and cooling to cut the energy they use by more than 80%. Using electricity and directly burning fossil fuels to heat water will become rare in the coming decades [4].
When talking about alternatives to fossil fuels, hydrogen often appears, which is a chemical element that makes up approximately 75% of the Universe [5]. Located mainly in stars and giant planets, it is a considerable source of energy. The first experiments related to hydrogen were observed at the beginning of the 19th century, in particular with the electrolysis of water and later with the development of fuel cells with hydrogen storage. It is still important to note that this fuel has only recently resurfaced. In fact, it is the ongoing energy transition policy in several countries around the world that has led to this energy source being considered as an alternative to replacing fossil fuels.
Hydrogen is an important energy source of the future. A hydrogen molecule releases approximately three times more energy than its gasoline equivalent. It should be noted that hydrogen is not an energy, but an energy vector. Hydrogen is a vector that is not present in a pure state in nature. It is therefore necessary to use energy to extract it from the water. From a molecular point of view, H20 is present throughout our planet. As a reminder, water is one atom of oxygen and two atoms of hydrogen (H2O). It is important to note that H2O represents almost 90% of the atoms (in number) present on our planet [5].
The climate emergency favors the emergence of renewable energy (solar and wind). These means of energy production are questioned because they are intermittent. They only produce electricity when conditions allow. The use of hydrogen can be, however, a solution to deal with the intermittency of the use of renewable energies by using them in the process to produce and store hydrogen, which consists of carrying out the following steps [5]:
• 1st step: through the electrolysis process, produce hydrogen from water. In fact, water is made up of hydrogen and oxygen (H2O) molecules. Using electric current with the use of solar and wind energy or another energy source, it is possible to separate water molecules and thus store hydrogen to be used in generating electricity and for other purposes. In the electrolysis of water to obtain hydrogen, there are two electrodes, one positive and one negative. The negative electrode is powered by hydrogen, while the positive electrode receives air. At the negative electrode, a substance separates hydrogen molecules into protons and electrons. While the electrons leave the negative electrode and generate a flow of electricity, the protons go towards the positive electrode with air. There, these protons mix with oxygen and, in the opposite direction to electrolysis, generate water and heat. This is how this type of fuel generates energy without combustion, producing only water vapor.
• 2ᵉ step: Once the hydrogen is stored, there are multiple uses. With the stored hydrogen, it is possible to produce electricity through a fuel cell. When associated with a fuel cell, this energy does not emit CO2. Water is the only residue from a used fuel cell. The fuel cell is an electrochemical device that converts the chemical energy contained in hydrogen into electrical energy and water. The hydrogen fuel cell is a type of battery in which the overall reaction of the process occurs using hydrogen: 2H2(g) + O2(g) => 2H2O + energy. There are numerous applications for hydrogen, such as the decarbonization of industry, electricity storage, road, sea or air transport, the supply of electricity in buildings and submarines. It can also be used in space vehicles, in backup energy, vehicular energy generation (electric and hybrid vehicles), stationary generation in industries and homes and portable generation as power for cell phones and notebooks.
One of the most important climate issues is that of the transport sector. In fact, today most transport runs on fossil fuels. The transport sector represents around 20% of greenhouse gas emissions in the world. One of the solutions envisaged to decarbonize this sector is, therefore, hydrogen. One can imagine hydrogen-powered vehicles. The combustion of this gas produces only water, this property makes it a serious candidate as a fuel of the future. The vehicles’ engines would be powered by hydrogen. There is the possibility of installing a fuel cell to equip the vehicles. Many manufacturers are interested in the possibility of installing a battery that supplies the car with electricity. Inside the battery, the hydrogen energy is then converted into electrical energy. In this scenario, hydrogen solves the problem of the autonomy of electric vehicles. The efficiency of hydrogen in a fuel cell is almost 50%, which is an exceptional value [5].
There are several ways to produce hydrogen based on water electrolysis. Some of them consume fossil fuels. Today, most of the initial production of electricity or hydrogen (depending on the process chosen) is of fossil origin. The energy transition must allow us to reduce our CO2 emissions, which is why we must prioritize a renewable energy source (hydraulic, solar, wind and biomass). This is why we distinguish several “types” of hydrogen [5]: 1) green hydrogen that is manufactured by electrolysis of water with the initial use of electricity from renewable sources (hydraulic, solar and wind); and, 2) gray hydrogen that is produced by chemical processes that involve the use of fossil fuels. Green hydrogen should be considered a priority because it is the fuel that would help our societies decarbonize in the face of the climate emergency. Hydrogen as a fuel is seen as an important part of a carbon-neutral future. However, its transformation from gas to fuel requires a large amount of energy. Therefore, it is important to use renewable energy sources so that the final product is called green hydrogen.
Although the most well-known use of hydrogen is probably in motor vehicles, there are many other possible uses. Fuel cells can serve as fixed power generation units for buildings. In some cases, they can also provide heat. Fuel cells are seen as potential power sources for aircraft. It is possible, for example, to use them as an emergency generating system. Furthermore, they can serve as an auxiliary power unit for the plane. Hydrogen can provide energy for the propulsion of vessels. However, this use is still in the early stages of testing and development. However, its use as an onboard energy source is already more advanced. There is a Norwegian project that aims to create a hydrogen-powered cruise ship. It is also possible for hydrogen to power service vehicles such as forklifts and trucks, as well as buses and trains [5].
A sustainable energy system will only be possible if, in addition to abandoning fossil fuels, energy efficiency is also greatly improved. Above all, the world would have to produce goods and services with a third to a half of the energy it currently uses. Technologies are now available that would quadruple the efficiency of most lighting systems and double that of new automobiles [5]. Improvements in electrical efficiency could reduce energy needs by 40 to 75%. Building heating and cooling needs can be cut to an even smaller fraction of current levels thanks to improved heating equipment and air conditioning [4].
REFERENCES
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2. SMIL, Vaclav. Energy and Civilization – A History. Cambridge. Massachusetts: The MIT Press, 2018.
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* Fernando Alcoforado, awarded the medal of Engineering Merit of the CONFEA / CREA System, member of the SBPC- Brazilian Society for the Progress of Science, IPB- Polytechnic Institute of Bahia and of the Bahia Academy of Education, engineer from the UFBA Polytechnic School and doctor in Territorial Planning and Regional Development from the University of Barcelona, college professor (Engineering, Economy and Administration) and consultant in the areas of strategic planning, business planning, regional planning, urban planning and energy systems, was Advisor to the Vice President of Engineering and Technology at LIGHT S.A. Electric power distribution company from Rio de Janeiro, Strategic Planning Coordinator of CEPED- Bahia Research and Development Center, Undersecretary of Energy of the State of Bahia, Secretary of Planning of Salvador, is the 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), A humanidade ameaçada e as estratégias para sua sobrevivência (Editora Dialética, São Paulo, 2021), A escalada da ciência e da tecnologia e sua contribuição ao progresso e à sobrevivência da humanidade (Editora CRV, Curitiba, 2022), a chapter in the book Flood Handbook (CRC Press, Boca Raton, Florida United States, 2022), How to protect human beings from threats to their existence and avoid the extinction of humanity (Generis Publishing, Europe, Republic of Moldova, Chișinău, 2023) and A revolução da educação necessária ao Brasil na era contemporânea (Editora CRV, Curitiba, 2023).
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