Deployment of Electric Induction Technologies into Cooktops Plates as a Part of Energy Sustainability

For a long time now, humanity has been facing the phenomenon known as “climate change”, a major challenge of which we must be aware of what we are doing so as not to affect ourselves or future generations. It is evident that, if what is sought is a sustainable energy future, the current energy model implemented in certain countries and regions of the world is not the most adequate and makes the achievement of this goal unfeasible. This situation threatens to greatly alter our ecosystems and our social structures, and one of the key actions to mitigate it is, undeniably, the generalization of the use of renewable energy sources; and specifically, the non-conventional sources, referring to solar and wind, technologies that comply with the principle of energy complementarity; however, there are other possible solutions such as the deployment of programs that consider efficient cooking technologies; involving with it is everything related to energy security and equity, as well as environmental protection. In this article, as a technology to be considered to reduce and mitigate the Greenhouse Gases (GHG) emissions, an analysis of the efficiency assessment of electric induction cooktops and the determination of their potential energy savings are carried out. The impact of these results is taken into consideration and a series of conclusions and recommendations for improvement are issued.


Introduction
"The development of cleaner and more efficient energy technologies and the use The recovery from the consequences of this last wave will not be easy; however, transformation is still possible, bearing in mind that there is an inseparable relationship between development, climate and energy, remembering that without energy we could not have the technology.
In order to curb the COVID-19 contagion, countries worldwide implemented confinement measures, this led to the interruption of economic activities, simultaneously causing a significant temporary reduction in CO 2 emissions, which was expected to be close to the reduction that the world would have to make each year to achieve the temperature increase target of the Paris Agreement. This situation has served to make us realize that meeting the goal of avoiding a global average temperature increase above 1.5˚C would imply important changes for society, and establish what is known as an era change.
Excessive emissions of CO 2 , which is a colorless, odorless gas composed of oxygen and carbon, are one of the main causes of global warming, a problem caused by human activity and aggravated by the long persistence of this gas in the atmosphere. The burning of fossil fuels for energy production, transportation and industry has been increasing to such an extent that the concentration of carbon dioxide in the atmosphere, measured at NOAA's Mauna Loa Atmospheric Baseline Observatory, reached a monthly average of 419.13 parts per million (ppm) in May 2021, the highest level since accurate measurements began 63 years ago [3]. The daily record of the referred concentration is maintained by the Scripps Institution of Oceanography of the University of California at San Diego and represented in the Keeling curve [4], as shown in Figure 2, which allows visualizing the existence of a clear correlation between the increase in atmospheric CO 2 concentrations and the industrialization process.
Due to the COVID-19 pandemic, global CO 2 emissions declined by approximately 5.4% in 2020; this event is considered the largest decline in history and is 4.5 times larger than that caused by the global financial crisis in 2009, as shown in Figure 3. Carbon dioxide emissions declined more than energy demand in 2020 because the pandemic affected oil and coal demand more than other energy sources, while renewable energy increased.

Sustainable Development
"Sustainable Development (SD) responds to the needs of the present moment without jeopardizing or compromising the ability of future generations to meet their own needs" [1] [9]. From the energy point of view, sustainable development is only possible if the energy system is also sustainable, and the latter must be based on renewable energies and policies that promote energy efficiency and savings. As shown in Figure 5, there are three independent and mutually reinforcing components of the SD: economic development (Economy), social development (Society) and environmental protection (Biosphere).  Undoubtedly, the key challenges of the 21st century are monitoring and mitigating climate change and adapting to it. At the heart of this struggle, both from a social and industrial point of view, is energy as a protagonist, as a central element of progress, development and growth of our societies and our economy.
However, this same element, which is fundamental for development, is also the main cause of emissions and, therefore, of climate change. While access to energy is relevant, it is central to poverty eradication, reduction of infant mortality, improvement of health, education, and promotion of gender equity among others; it is therefore clear that without universal access to modern energy services, the SDGs cannot be achieved. Figure 6 shows the set of necessary actions, proposed by the International Atomic Energy Agency (IAEA), to facing climate change, identified as one of the greatest environmental challenges affecting the planet Figure 6. Triangle with roadmap and actions to be taken in order to combat climate change. Source: International Atomic Energy Agency-IAEA [11]. Smart Grid and Renewable Energy and humanity. In short, these key challenges correspond to the fundamental principle of resilience.

Energy Trilemma
Energy efficiency, renewable energies and energy savings are not isolated activities, as they were seen some years ago; nowadays these three concepts are integrated and enhanced through new trends such as electromobility, district heating, efficient cooking, distributed generation, storing or cogeneration and sustainable construction, to mention just a few. It is this comprehensive vision that we refer to when we talk about energy sustainability. Figure 7 summarizes this schematically.
The World Energy Council (WEC) has been working on what it denominates as Energy Sustainability, which it defines as the balance that exists between three dimensions, referring to: energy security, energy equity (taken as access to energy and its affordability; i.e., that energy is cheap) and mitigation of the environmental impact in energy production; i.e., environmental sustainability. This is what defines the energy trilemma, a choice between three options, which are (or appear to be) contradictory to each other. Thus, in order to build a strong basis for prosperity and competitiveness, individual countries must balance these three dimensions, as shown as Figure 8.

The Electric Induction Cooktop
To understand how an electric induction cooktop works [12], it is necessary to   Consequently, if an electric current of varying frequency generates a magnetic field, this varying magnetic field induces an electric current in a closed circuit; the latter, in turn, is related to a non-conservative electric field. The induction stove is a type of vitro-ceramic stove; and in essence, under the cooking zone-the main element-there is a flat copper coil with a spiral shape ( Figure 9), through which an electric current of variable frequency (20 -100 kHz) is passed, which generates alternating magnetic fluxes. This current, therefore, produces a magnetic flux density with the same frequency with which the current in the coil varies, whose vec- where: a is the radius of the flat, spiral-shaped copper coil; h is the height above the coil at which the magnetic flux density is being determined; N is the number of turns of the coil, assuming that they are uniformly distributed and that each turn is a perfect circular spiral; i is the perfect circular loop element.
Note: a small computer program may be used if the number of turns N is large.
This magnetic field does not cause any interaction if no electrical conductor is present. The containers (pots, pans, frying pans, casseroles, bowls, etc.) used in induction hobs must be made of metallic materials that have the following properties: 1) excellent electrical conductivity, ensuring that the electrical resistance of the container is very small, which allows the internal circulation of the so-called induced currents; and 2) ferromagnetic, in order to take advantage of magnetic hysteresis, which is the property of these materials to present opposition to the change in magnetic flux density.
A. Tama Smart Grid and Renewable Energy propagate in this type of material and its intensity decreases rapidly.
Likewise, said alternating magnetic field, inside the base of the bowl, also repeatedly magnetizes and demagnetizes the referred material, causing the iron molecules to vibrate between 20,000 to 50,000 times per second, and the friction between them produces additional heat (loss by hysteresis). The superposition of the heat released by the Joule effect, the heat released by the skin effect and the heat due to hysteresis losses are used to cook food.

Liquefied Petroleum Gas (LPG) as Fuel
Liquefied Petroleum Gas (LPG) is obtained during the refining of crude oil, as one of many by-products. It can also be obtained from the refining of natural gas (in this case another product with different characteristics). It is a mixture of propane C 3 H 8 and butane C 4 H 10 -light hydrocarbons, which are organic compounds consisting only of carbon and hydrogen-usually in a 70% -30% or 60% -40% ratio, depending on the target product, whose combustion ratio is indicated in expression (2). LPG evaporates at normal temperatures and pressure, which is why it is distributed or supplied in the classic pressurized balloons or cylinders in a liquid state, hence its liquefiable identity. It is a petroleum derivative with a high calorific value and a higher density than air, used in cooking food, in home heating, as fuel for vehicles and refrigerant, as fuel in furnaces, dryers and boilers in different types of industries, in internal combustion engines and in gas turbines for electric power generation, among others.

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The calorific value or heat of combustion is the amount of energy (or heat) released by a given quantity (kilograms, pounds, cubic meters) of substance (fuel) during its complete combustion (oxidation reaction). In other words, the calorific value is the capacity of a fuel to give off heat when it is burning. Hence, assuming a calorific value of 11,500 kcal/kg for a domestic LPG cylinder (15 kg), the amount of energy (or heat) capable of being released is as shown in Figure 11.

Cooking Efficiencies
Taking into consideration the heat transferred to the pan or bowl that remains on the glass ceramic surface, in studies carried out by the United States Department of Energy (DOE), it was determined that the efficiency for different types of cooktops is as shown in Table 2.
In this regard, it is worth noting that the efficiency depends on the size of the pan used compared to the size of the flame/heating surface. Therefore, the efficiency values above are based on an ideal configuration.
Considering the cooking efficiency for each of the sources, it is perfectly possible to decide, by performing a cost analysis, very simple and perfectly comparable, which of them is economically more convenient to the interests of each user. For this purpose, let us suppose that we want to boil 10 liters of water (equivalent to 10 kg of water) that are at room temperature (25˚C). Thus, the amount of heat and energy required for this purpose is that indicated in (3) and (4) A. Tama Smart Grid and Renewable Energy Figure 11. LPG calorific-energy-electricity equivalent.
From the results obtained in Table 3, it can be clearly seen that it is slightly chea-

The Promising of the Electric Induction Cooktop
In the most elementary way possible, the term "Induction" is linked or related to the term "Reduction", because with the use of this type of cooktops ( Figure   12): 1) The heat of the cooking environment is reduced (making it cooler); 2) Cooking times are reduced (linked to effectiveness); and, 3) Energy consumption is reduced (linked to energy efficiency), thereby hopefully reducing the energy bill.
Because of the nature of the science behind the heating method, induction cooking or heating technology offers significant advantages and slight disadvantages over traditional technologies, which are summarized in Table 4 and detailed below.

PROS
Higher energy efficiency: all energy is utilized, since only the energy needed to heat the vessel is emitted, not the glass or those areas not covered by the vessel.
This higher energy efficiency is present in the reduction of heat transfer losses by radiation to the environment.
Quicker heating: heating is faster and the heat is distributed more evenly.   Acquisition costs: electric induction cooktops are more expensive than any other regular cooktop.

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Electricity supply: the failure or inadequate supply of electricity can cause the cooking process to stop.
Emissions of electromagnetic radiation: due to operating with EM fields of variable frequency, which correspond to the non-ionizing region of the EM Spectrum; however, the heating effect produced by induced currents is very low.
Steep learning curve: when changing to an electric induction cooktop, the user will need to quickly change some of his or her cooking habits.

Technology Substitution Program (TSP)
From the results obtained and the comparisons made between the different types of cooktops, it is evident to conclude that it is convenient to replace these other technologies with electric induction cooktops; for this purpose, a serious Technological Substitution Program should be developed, whose deployment and implementation should be executed as soon as the feasibility of electric generation exists. For the TSP to be successful, it must comply with the characteristics detailed below and shown in Figure 13.
Specific: The clearer and more detailed the objective is, the easier it will be to establish actions to achieve it, clearly defining to what and with which sectors the implementation of the PST will start.
Measurable: An objective must be measurable through indicators that will al- Attainable: Objectives must be reasonable; the target universe and its limits must be defined in a responsible manner.
Relevant: In addition to being attainable, objectives must be relevant, i.e., they must be important for development. A relevant objective will be aligned to the general objectives. For example: economic savings for a given country and for consumers, incentive for producing companies, generation of jobs, and reduction of greenhouse gas emissions among others.

Motivations for TSP's Implementation
Hand in hand and correlated with the implementation of this technological program, is undoubtedly the technical, economic and financial impact on the electric power distribution companies in the country that decide to continue with the deployment of electric induction technologies in cooking, because the operation of the same, will generate a severe increase in the demand for power and energy; Therefore, corrective measures must be foreseen in a planned manner in the electrical distribution and transmission networks, corrective measures that imply improvements and repowering of the conductors of the different circuits, division and increase of those, improvement of the electrical service connections; without leaving aside, of course, the compensation of the reactive energy that these induction plates will demand; which will be necessary, if its compensation is not considered at the moment of its manufacture or assembly. The main motivations for the implementation of the TSP are detailed below.
Obtaining energy savings: Through efficient cooking and the use of appropriate appliances, there would be a reduction in radiant heat and direct and indirect economic savings.
Contributing to energy security: Through improvements to the national electricity system, there would be an increase in the reliability of energy infrastructures, increasing the capacity to meet current and future demand.
Contributing to energy equity: Through energy security and the deployment of electric grids, energy supply would be accessible and affordable for the entire population.
Contributing to the mitigation of environmental impact: Through the technological replacement of cooktops, linked to energy efficiency and savings, there would be a reduction of pollutants and GHG emissions, improvement in social and environmental conscience, reduction of deforestation and its global consequences, as well as a suitable environment for the development of sustainable energy systems.

Energy Use and Payback Period
In order to be able to adequately prepare A residential market study carried out particularly on cooktops concluded that induction technology. a to be at least $400 USD more expensive than comparable LPG cooktop products. b to be at least $300 USD more expensive than comparable electric cooktop products.
Consumption (AEC) for an electric coil cooktop and an electric smooth cooktop is 240 kWh and 250 kWh, respectively; likewise, for an electric induction cooktop and a domestic LPG cooktop it is 190 kWh and 330 kWh, in that order. Depending on the country or region to which this study is being extrapolated, these reference values may vary, and will undoubtedly be a function of usage and/or good or bad cooking habits. Additionally, the energy costs associated with this activity will be determined based on the information contained in Table 3.
The following has been considered in this study: 1) For the electric coil cooktop, the baseline efficiency applies to a cooktop composed of four radiant coil elements. This cooktop was assumed to consist of two 6-inch elements and two 8-inch elements. The electrical input ratings of the 6-inch and 8-inch elements were assumed to be 1250 watts and 2100 watts, respectively; 2) For electric smooth cooktops, the baseline efficiency applies to a cooktop composed of four solid disk elements. This cooktop was assumed to consist of two 6-inch elements and two 8-inch elements. The electrical input ratings of the 6-inch and 8-inch elements were assumed to be 1500 watts and 2000 watts, respectively; 3) For the LPG cooktop was assumed to consist of four conventional (open) gas burners. Each burner was rated at 9000 Btu/h; 4) All electric and gas cooktops are equipped with an electronic ignition device, so that the energy factor is equal to the cooking efficiency; 5) The technical lifetime for all cooktops is 19 years; 6) The payback period refers to the time when the energy savings due to efficient induction cooking have paid for the additional cost of the induction unit.

Discussion
With the application of the TSP, energy savings will be achieved that go hand in A. Tama hand with the reduction of pollutants, but regardless of this, and despite having the latest or best technology in electric induction cooktop in our hands, the small savings in the energy bill will not compensate the additional costs of acquisition and installation of those, the short-term savings should not be confused with the overall reduction of costs.
To promote energy efficiency, not only should environmentally responsible norms or standards be established and a regulatory framework developed, but also consumer awareness and education are crucial issues.
To improve energy access at local, regional and global levels, new energy technologies must be developed, new infrastructure must be built and obsolete infrastructure must be replaced. Large investments are necessary; therefore, market conditions capable of attracting long-term investments must be supported.
For the private sector to invest in environmentally responsible and energy-efficient technologies, intellectual property rights must be strongly protected.
With the implementation and deployment of the TSP, and if any type of energy subsidy is considered, as Ecuador once did in its time, it should be analyzed with care, with the purpose of causing the least possible social impact, remembering that the balance of economic, financial, social and environmental returns must coexist.
It is worth pointing out that with this TSP, the use of domestic gas will not disappear, since the ovens-an integral part of a "stove" as a whole-will remain to be operated with LPG or electricity but not with magnetic induction, at least for the time being.
Even if there is an oversupply of energy, in order to simultaneously improve the three dimensions of the energy trilemma: energy security, energy equity and environmental sustainability, there will always be the possibility of failure in the supply of electric service, since no system is invulnerable to atmospheric events, bad maneuvers, lack of coordination or even sabotage. Therefore, it would be necessary to analyze the alternative of considering that electric induction cooktop include gas burners.
Finally, it is important to consider that since this TSP will be focused initially on rural areas, there should be Customer Service Centers (CSC) that have the technical capacity to provide an immediate response for repair or replacement of the cooktop plate, in order to avoid the production of unnecessary electronic waste.

Conclusions
1) Table 3 clearly shows that, with induction technology, the lowest annual energy consumption is achieved; besides, due to its high cooking efficiency, the amount of energy used for cooking is lowest. Similarly, according to 2) Energy use for cooking-whether gas or electricity-is a very small percentage of typical household energy consumption (about 5%), so there are more important places or activities to put effort in relation to savings. However, any energy savings, above all, a relevant reduction of GHG emissions, will contribute greatly to sustainability management.
3) Gas is a primary energy source, while electricity is a secondary energy source; this is because coal or gas is used to generate electricity. By the time electricity reaches households, much energy has already been lost in the generation, transmission and distribution stages. Therefore, if these losses and efficiency are taken into account, both sources (gas or electricity) could be equal and it is personal preference or economic value that should guide the decision, without losing sight of the existence of mandatory nature of their use as a state policy.
4) The community is concerned about electromagnetic emissions, which are lower in electric glass-ceramic systems than in induction ones; however, the latter are much more efficient than the former. Thus, the operating time of the equipment (and thus the duration of exposure to such emissions) is much shorter in induction stoves. For now, the available data suggest that, if there are non-thermal effects of non-ionizing radiation absorption on human health, such effects are not so profound as to be easily discernible. In fact, according to expression (1), the magnetic flux density by the exponent to which it is raised, decreases very rapidly with distance. So, if exposure occurs, its effects will be minimal and would not pose a risk, except to users with active implants, and more specifically, to people implanted with pacemakers.
5) The Technological Substitution Program (TSP) together with efficient cooking must be seen as the means to guarantee inclusive decarbonization, which does not leave any community behind, becoming an essential part of humanizing the energy transition. 6) Cost, in fact, is the greatest barrier to the adoption of induction technology [18]. In Table 5, the payback period by technology substitution was determined; however, in these calculations, the cost related to the acquisition of inductioncompatible cookware was not considered. This could represent several hundred dollars, which would be added to the induction technology premium, depending on the culinary needs of the user, of course.
7) The deployment of induction cooktops will undoubtedly lead to the rein-A. Tama Smart Grid and Renewable Energy forcement of energy infrastructures, and if to this is added the diversification of the energy mix through renewable sources, then the countries that adopt this study will be closer to achieving a sustainable energy system, and will be guaranteed to obtain a balanced score in the general index of the Energy Trilemma.

Data Availability Statement
The data used in this study can be obtained by contacting the corresponding author.