Fernando Alcoforado*
This article aims to present what would be the future required for the production and consumption of energy in the world based on the use of clean and renewable energy. Energy is an essential input for living beings and for economic and social development. It can be said that the most basic need of living beings is the search for energy to keep their bodies functioning. This aspect, the fulfillment of physiological needs, predominated in the history of humanity until it was discovered that he could control forms of energy that would be useful to him, such as fire, which represented a very important milestone in the dominance of human beings, using thermal energy to be able to cook their food and keep warm. A few millennia ago, renewable energy represented by wood and scarce hydraulic and wind power was also used. The domestication of animals provided humanity with mechanical energy for transportation, agriculture, etc. However, it was only with the advent of the Industrial Revolution, around three centuries ago, that the use and production of energy took on a fundamental role in replacing men and animals with machines.
From the domination of fire 750,000 years ago to the advent of the Industrial Revolution, there was no major evolution in the way humanity used energy. However, with the Industrial Revolution that occurred in England in 1786 and the resulting industrialization process and the development of means of transport, the need for energy increased and new primary sources, with greater energy density, were introduced. The use of mineral coal as an energy source marked the end of the era of renewable energy represented by wood and the meager hydro and wind power, to begin the non-renewable era of energy, the era of fossil fuels. The use of electricity and the invention of electrical machines in the 19th century, together with the introduction of motor vehicles, laid the foundations for the introduction of the modern consumer society, characterized by an energy intensity never seen in the history of humanity.
With the advancement of the industrialization process and the development of means of transport, 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. More recently, after the Second World War, nuclear energy seemed a promising alternative for generating electrical energy, but suffered a major setback due to the nuclear accidents at Chernobyl in 1986 in Ukraine and at Fukushima in 2011. There is no doubt that human activity 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.
The main reason for the existence of environmental impacts from the generation, handling and use of energy 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 total, with only 12% coming from renewable sources of energy. This enormous dependence on non-renewable energy sources has led, in addition to the permanent concern about the depletion of these sources, to the emission of large quantities of carbon dioxide (CO2) into the atmosphere. As a consequence of the excessive use of fossil fuels, the carbon dioxide content in the atmosphere has progressively increased, leading many experts to believe that the increase in the average temperature of the Earth’s biosphere, which has been observed for a few decades, is due to CO2 emissions and other gases in the atmosphere, already generically called “greenhouse gases”.
To avoid the catastrophic future that is predicted for humanity resulting from global warming, it is imperative, among other measures, to reduce global greenhouse gas emissions by replacing the current global energy matrix based fundamentally on fossil fuels (coal , oil and natural gas) and in nuclear energy, by another global energy matrix structured based on renewable energy resources (hydroelectricity, biomass, solar energy, wind energy and hydrogen) to avoid or minimize global warming and, consequently, the occurrence of catastrophic changes in the Earth’s climate.
There is no doubt that human activities on Earth cause changes to 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 of energy. 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.
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 energy sources 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 and China [1].
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. 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 [2]. 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 of fuels fossils (oil, coal and natural gas) and nuclear energy. Exceptionally, it could use natural gas because it is the least polluting fossil fuel and nuclear plants because they are sources of clean energy in the transition phase. Until reaching the ideal condition, 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].
Science and technology 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. 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 they are aimed at to achieve the central objectives 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 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 shadow of a doubt, the rational way to guarantee the sustainability of planet Earth for current and future generations.
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.
When talking about alternatives to fossil fuels, hydrogen often appears, a chemical element that makes up approximately 75% of the Universe. 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 the storage of hydrogen. It is still important to note that this fuel has only recently resurfaced. In fact, it is the energy transition policy underway 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 [4].
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 [4]:
• 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 using hydrogen is: 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 33% of greenhouse gas emissions in Brazil, 30% in France and 20% worldwide. 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% that is exceptional [4].
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 [4]: 1) green hydrogen which is manufactured by electrolysis of water with the initial use of electricity from renewable sources (hydraulic, solar and wind); and, 2) gray hydrogen which 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 pay attention to the source of this energy so that the final product is the so-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 generator system. Furthermore, they can serve as an auxiliary power unit for the plane as a whole. Hydrogen can provide the energy for the vessel’s propulsion. 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 [4].
A sustainable energy system will only be possible if, in addition to abandoning fossil fuels, energy efficiency is also greatly improved. A sustainable energy system will only be possible if energy efficiency is 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 [5].
Biomass and hydroelectric power provide about 13% of the world’s energy. Biomass alone meets 35% of the needs of peripheral and semi-peripheral capitalist countries. 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. In a few decades, the Sun can 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 [5].
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 also 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 avoid compromising the global environment.
REFERENCES
- G1.GLOBO. AIE: mundo se encaminha para futuro energético insustentável. Available on the website <http://g1.globo.com/mundo/noticia/2011/11/aie-diz-que-mundo-se-encaminha-para-futuro-energetico-insustentavel.html>), 2011.
- LASHOF, D.A. & TIRPAK, D.A.orgs. Policy options for stabilizing global climate. Washington, DC, Environmental Protection Agency, 1989.
- ALCOFORADO, Fernando. Energia no mundo e no Brasil. Curitiba: Editora CRV, 2015.
- SIRENERGIES. L’hydrogène, énergie du futur? (Hidrogênio, energia do futuro?). Available on the website <https://www.sirenergies.com/article/hydrogene-energie-du-futur/>, 2022.
- ALCOFORADO, Fernando. Aquecimento global e catástrofe planetária. S. Cruz do Rio Pardo: Viena Gráfica e Editora, 2010.
* Fernando Alcoforado, awarded the medal of Engineering Merit of the CONFEA / CREA System, member of the Bahia Academy of Education, of the SBPC- Brazilian Society for the Progress of Science and of IPB- Polytechnic Institute of Bahia, 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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