Comprehensive decision-making considerations in the transition to electrification transportation system in a developing country

Abstract

Introducing suitable alternatives to the existing fossil fuels can provide insightful aspects of the expected benefits. In the energy sector, the transportation system is one of the key contributors to fossil fuel consumption and greenhouse gas productions. To elaborate on the performance of each introduced alternative, two perspectives are considered; short-term and long-term evaluations. In the short outlook, the PROMETHEE method is used for evaluation. Six scenarios are introduced based on the technical, economic, social, and policy criteria and each scenario benefits from different weights. In this scheme, the impacts of evolutions in the battery applications in the vehicles are investigated. Based on the short-term study, CNG and gasoline are considered the best options for the fuels of vehicles in Iran by taking into consideration the current situation. By viewing the technical and economic criteria, it was concluded that the Li-Ion battery provides better performance in comparison with gasoline in the long run. By 2040, the number of EVs will reach 10% of the overall vehicle production. It is obtained that the benefits of the electrical vehicles’ presence as the alternative to the internal combustion vehicles can provide growing interest in this outlook from 2.02 × 10⁶ US$ in 2025 to 17.55 × 10⁸ US$ in 2040.

Introduction

As technology continues to be on the rise, fewer modern technologies are losing their value. There is a broadly held insight in the world that internal combustion vehicles are the main contributors to air pollution while some still hold to the view that the latest improvements in the vehicle industry can improve the environmentally friendly behaviors of these technologies. In this case, widespread investigations have been conducted to elaborate on the novel aspects of electrical vehicles as practical solutions for this dilemma. To overcome the dominant problems associated with internal combustion vehicles, electrical-based technologies have been developed to introduce the latest developments in tandem with these vehicles. Near to zero carbon emissions, high potential to prevalence, and lower dependence on the erratic trend of fossil fuel's cost made the electrical vehicle (EV) an interesting and promising option to replace internal combustion engine vehicles (ICEV)^1,2.

The international panel on global warming initiated the transportation subdivision to be one of the greatest problematics to make eco-friendly³. Two main factors of these problems are (1) an absence of reasonable green substitutes to fossil fuels that might effortlessly surpass the market and (2) the minor portion of fuel prices in the total charge of presented transport amenities. Henceforth, economic modeling commonly indicates that carbon taxes have a comparatively slight impact on emissions justification in the transportation subdivision⁴. Conversely, fuel price is a considerable portion of the price of power production from fuels, and many budget-friendly, near-zero-emission replacements to fossil fuel resources are accessible as well as renewable energies, or carbon capture systems. In addition, a carbon tax inspires more electrification of consumer facilities owing to the charge of power increases reduced amount of the price of fossil fuels with the related carbon taxes⁵. International studies of climate change often short come in the acceptance of novel skills⁶ and therefore, the swift penetration of Battery electric vehicles (BEVs) taking place in the road transport sector from developments in BEV operation while policies with prices have not been projected. Significant battery price decreases have been attained in the past decades as the normal cost of a pack of Li-ion battery has reduced from 1000 USD/kWh in 2010 to 132 USD/kWh in 2021^7,8,9,10. Latest developments in the durability of Li-ion batteries would guarantee BEV batteries deliver a million miles of usage that can endure the lifetime of the vehicle¹¹. Substantial advances in battery features and charges are moderating the price of BEVs.

Despite the attainable environmental profits related to the introduction of EVs, the penetration of EVs into the vehicular population has been anticipated or desired by many governments and analysts. But the expected speed is going slower than it should be. For this study, EVs use electrical motors for propulsion, and energy is deposited in batteries that can be recharged by connecting to the domestic grid or public charging stations this is considered a vehicle that uses many difficulties to stand in the path of EVs becoming a significant part of the automotive market. One of the main reasons for the low consumer acceptance of EVs is the concept that electric vehicles charge more than their ICEV counterparts. The well-known fact that EV purchase prices are higher than comparable ICEVs may deter potential EV customers. However, consumers often do not consider the total cost of ownership when choosing a vehicle¹².

Attention to EVs is based on their tender for low or no generated emissions. Though, as Lave et al. ¹³ stated the straight tail-pipe discharges are merely one characteristic of the ecological effects of EVs. To confirm that the advancement of EVs to diminish greenhouse gas production from transportation systems does not contribute to other unwanted outcomes, it is thoughtful to carry out severe, scenario-founded environmental valuations of projected knowledge before their extensive approval. Life cycle assessment is the instrument of selection for associating the environmental influences of transport selections as it counts resource usage and environmental emissions with the entire life cycle of products. At this point, three categories of vehicles are distinguishable. BEVs which employ just an electrical motor, ICEVs benefit from hybrid electric vehicles (HEV), and internal combustion engines (ICE) have the benefits of both aforementioned types as run by electric motor and ICE^14,15.

To elaborate on the conducted studies on the ICEVs and EVs, it is apparent that the number of related research that focuses on comparative studies is limited. In most of the carried-out work, technical, economic, and LCA have been employed as the calculative factors to evaluate the performance of each category. Liu et al.¹⁶ put forward research to assess the operation of ICEVs and EVs from an economic point of view. The obtained results have shown that the elective expenditure on home charger installation and substitute transportation enhances the associated fees. Sabri et al.¹⁷ put forward a review of the architecture of HEVs and their associated energy management strategies. It was stated that the objective of HEVs is to deliver an efficient performance of these vehicles by considering technical parameters. Biresselioglu et al.¹⁸ investigated the impact of EV developments throughout Europe. Regarding the mentioned results on a general and innovative evaluation of the recent literature on EVs in Europe, three stages of decision-making have been defined: Official Social Units, Individual Units, and Collective Decision-Making Units. Outcomes detect that the key obstacles are insufficient charging infrastructure; financial boundaries and cost concerns; procedural and working limitations; absence of trust; info and familiarity; inadequate provision of power and raw materials; and feasibility worries. Therefore, key promoters seem to be environmental, financial, and methodological profits from EVs, in addition to individual and demographic factors. Yuan et al.¹⁹ traced the impact of the electrification of transportation on the energy markets. In their work, they have used the bottom-up model as a methodology in the road transportation sector. Through this research a complete energy system method that combines a mentioned model and EnergyPLAN tool as proposed for transportation electrification. The EnergyPLAN software is a replication instrument for energy scheduling for the smart types of energy systems, which in the last decade has been extensively employed in EV penetration works. Lund et al.²⁰ examined the impact of EVs in combining wind energy by associating diverse charging approaches. Bellocchi et al.²¹ led a study on the constructive connections between EVs and renewable energy systems. Dorotic et al.²² introduced and studied a carbon-free island energy facility by applying only erratic renewable energy systems in integration with a total part of chargeable vehicles.

In order to propose a sustainable pathway for road transportation in the future, the decarbonization potentials are reviewed by Yu et al.²³. After considering the required energy sources for transportation, fossil fuels were determined as the main source of energy. They have reported that under the current energy mix in the electricity grid, the region of HEVs and plug‐in hybrid electric vehicles can accomplish comparable main energy efficiencies comparing BEV, but with 10%–20% more GHG productions over operation. Andreassen et al.²⁴, compared the policies, technological, and economic parameters for non-fossil-based technologies in the decarbonized transportation division. Dirnaichner et al.²⁵ provided a comprehensive assessment of the life-cycle impacts of the decarbonized scenarios for European road transportation by considering the environmental parameters of the related technologies. Based on the obtained results, light-duty cars are categorized as the most suitable eco-friendly options in all types of vehicles. Glyniadakis et al.²⁶ carried out an analysis of the different scenarios for the light vehicles fleet for Brazil as the case study. Based on the outcomes, the distinction of biofuel in low-carbon strategies was not neglectable. The most sustainable contribution of EVs in the Brazilian power-driven mix is estimated to be 38%, representing promising setups for growing the usage of EVs. For another study for Brazil, Da Silva et al.²⁷ assessed the decarbonization scenarios for the transportation systems considering economic and environmental factors. While EV was introduced as the preferable option, the strategy that diminishes the maximum emissions embraced the development of renewable power production and employment of CO₂ tariff. By considering different scales for various case studies, a swift transition toward the decarbonized scenarios was elaborated by the specialists in this field^28,29,30.

Furthermore, considering the existing literature, most studies have concentrated on the electrification aspects based on the topographical scales of cities or countries³¹, in that way disregarding the evidence that the energy systems are not remote from an overall point of view, (apart from certain systems e.g. isolated islands)³². Breetz et al.³³ studied the influence of vehicle electrification in the United States. Calculated indexes for the operational parameters of the EVs revealed that financial incentives from the government were required to turn the battery-powered vehicles cost-effective and competitive in comparison with conventional transportation systems. It was noted that the efficiency of economic factors can be improved provided that the technological specifications lead to considerable reductions in the associated costs with the investment, operation, and maintenance charges. Hawkins et al.³⁴ listed and reviewed the environmental superiorities of the EVs setting side by side the conventional vehicles. In this research, the life cycle inventories (LCI) were employed as a powerful tool to assess the EVs’ performance for an impactful consequence in global warming potential (GWP) reduction if only the high-efficiency systems with compatible specifications were introduced. Shirazi et al.³⁵ conducted a comparison between EVs and compressed natural gas (CNG) based vehicles from a financial point of view. It was specified that the widespread advancements of EVs depend on the technological, social, and economic limitations to find appropriate conditions to grow.

As presented in the literature, a limited number of researches have been put forward on the EVs performance in a transition to the most developed technologies considering the traditional infrastructures in developing countries. In this work, a case study is carried out to investigate the benefits and limitations of the EVs compared to the conventional ICEVs. To elaborate on this issue, Iran’s transportation system is considered a prime example of developing countries to be assessed from different points of view. To the authors’ best recollections; it is conspicuous that a similar feasibility study has not been carried out in Iran for similar conditions. In the presented research, economic analysis has been employed to assess the potential progress in electrification from fossil fuel consumption. The intended results are deemed to be used in the decision-making processes for the applicability of EVs. In this case, two schemes are considered to elaborate on the performance of this transition; short-term and long-term studies. Accompanied by global attempts and considerations and concerning the certain necessity for adjustment of Iran's policies for the road transport fleet, evaluating the potential fuels is unavoidable, while this research presents novel outcomes for this concern. In view of the present and short/long terms Iran's proved resources’ conditions, industrial situations, and feasibility and environmental matters, the resolution for this study may deliver a supportive vision on the way to modification and replacement of fuels in the road transportation division and bond the academic and policy gaps for a developing country (Iran) as the case study.

In this work, to elaborate on the electrification aspects of the transportation sector, Iran is taken as a case study. Iran is a developing country located in the Middle East and enjoys a wide range of valuable mineral resources. One of the most important resources that can be found in Iran is oil which made this country one the most oil producers in the world³⁶. In this respect, due to the high subsidies by the government, the cost of gasoline and oil is relatively low. This has been a powerful cause of developing fossil fuel consumption by citizens. This high rate of fossil fuel use by individuals has pulled the trigger for environmental degradation, ecological contaminations, economic crisis, etc. in different levels of social lives³⁷. To commit to a course of action for confronting the drawbacks of fossil fuel consumption, different strategies have been presented. Renewable energy, hydrogen, batteries, nuclear power, biomass, and geothermal energy are the main alternatives to fossil fuels. Among them, batteries are promising and compatible options to be used in transportation systems. Proper energy density, low discharge, non-toxic materials, and instant readiness are the main excellencies of batteries. Considering all of the influential parameters in the energy sector as well as considering the technological advancements, batteries are the propitious and applicable choice for Iran. In this case, as indicated in Fig. 1, the transportation system contributed the most in comparison with other industries while around 51.67% of the overall fossil fuel consumption belongs to this sector. It is understandable from the information provided that its substantial share in utilizing fossil fuel is more than all other industries combined. In this way, the significant influence of the transportation system on fossil fuel consumption is conspicuous.

Fig. 1

The share of fossil fuel consumption in different sectors of Iran’s industries^40,41.

It can be inferred that by increasing the capacity of power generation in Iran, the potential for further application can be investigated while various consumers can be introduced. Therefore, besides the household and industrial applications of surplus electricity production, EVs can seek more benefits through this upward trend. It should be noted that regarding the expected numbers of EVs, additional advancements in electricity power generation would be required. Based on the latest statistics, Iran produces around 1 million cars per year while only 1% of the delivered vehicles are powered by electrical power^38,39. Hence, a potent potential for electrification in Iran’s vehicle industry can be found that can be fulfilled through a comprehensive program on the national scale.

Iran has projected to reach a sustained car production until 2031⁴². Based on the obtained data (Fig. 2), until 2022, the car production from total point of view followed a consistent trend and it is deemed to continue this procedure. It should be noted that there is no data availability from vehicle companies to state their long-term programs for the future. However, this objective is taken into account in this study. To present these data, the related references^43,44,45 are used to yearly data. As can be observed, the total number of vehicle production is highly influenced by the number of sedans and SUVs while other types of cars (pickups, vans, buses, and trucks) have a minority share of the overall total. Moreover, the EV ownership rate would be affected by political, economic, and social factors that provide an erratic trend. The reason for this trend is based on the fuel price and economic status of the society which appears to be effective. To elaborate on the reasonable justification for this trend, the price of gasoline plays a pivotal role in contributing to the growth or plunge in the purchase of EVs. To be more precise, a clear visual image of the gasoline price in Iran is presented in Fig. 3. An effective parameter in this trend is the variations in the price of gasoline while selling the fuels to the citizens and internal consumers is based on Iran’s Rial and based on its relative value against the US dollar and exchange difference; the year 2022 experienced a great fall in the worth of the intended fuel. As turned conspicuous, the price of fuels in Iran has experienced a great deal of fluctuations over the recent years and there are no sustained predictions.

Fig. 2

The number of car production based on the different types in last years^43,44,45.

Fig. 3

The price of gasoline over 20 years⁴².

It should be noted that Iran is one of the greatest carbon producers in the world (by total emission and per capita). In this case, a transition to electrification can prevent greenhouse gas (GHG) emissions from being released into the environment. In this case, the environmental benefits of using vehicles without emissions can be considered. Through this process, the benefits will be doubled as the contribution of the transportation system to GHG emission is presented in Fig. 4.

Fig. 4

CO₂ emission in Iran by different sectors⁴⁶.

Research methodology

To assess the technical and economic influences of the electrification transitions in the transportation system in Iran, a comparative investigation is intended to be put forward. The chief aim of this assessment is to estimate the possible benefits of the replacement of fossil fuels-based vehicles with EVs. In this way, two sections of the technical and economic analyses can be conducted. To investigate the effective aspects of electrification in Iran, a comprehensive comparison is required to measure the performance of the intended scheme. In this case, the PROMETHEE method is taken into consideration.

PROMETHEE technique

The Preference Ranking Organization METhod for Enrichment of Evaluations (PROMETHEE) is the expressive supplementary geometrical analysis for collaborative assistance. In this method, there exist preference priorities based on the designed criterion while the function with higher preference is more preferable. This method is a multi-criteria decision-making technique to rank and assess a set of substitutes based on several (in some cases contradictory) criteria. This method was established by Brans and Mareschal in the 1980s⁴⁷. The method is mainly valuable in states where a decision-maker is required to pick among numerous substitutes, respecting different quantitative and qualitative features. In this method, first, the alternatives and criteria are introduced while the criteria are effective in minimizing or maximizing the alternatives. This methodology is based on a matrix in that the alternatives and criteria are represented as rows and columns, respectively. Considering the criterion, a most favorable function that interprets the alteration in scores among couples of substitutes into an objected degree is selected. Following the procedure, a favorite index that sums the preference degrees' overall criteria is calculated. The obtained index shows the desirable preference of that alternative over others. To conclude, considering the net rankings, strategies are ranked from the most ideal to the least favored.

It should be noted that being straightforward and simple, having high potential for flexibility, no necessity to normalize, and visual illustration are the main plus points of this technique while requiring the weights assignments, difficulty in large problems, and being highly reliant on the preferences and judgments of the decision makers are categorized as the undesirable features of this method⁴⁸. Figure 5 represents the flowchart of the PROMETHEE technique.

Fig. 5

PROMETHEE technique flowchart.

The prioritization function pj (a, b), represented as a tool of the alteration amid two substitutes for involved standards, can be determined distinctly for all criteria to denote one alternative extent of desire to other quantitates. This formula is indicated as pj (f(a), f(b)) where its value is constantly from 0 to 1⁴⁹.

The lesser the function is, the superior the insignificance of the decision-makers would be also closer to 1, more fondness is expected. Accordingly, the function of related favorite P(a, b) of ‘a’ relating to ‘b’ can be signified as follows:

$$P\left( {a,b} \right) = \left\{ {\begin{array}{*{20}l} 0 \hfill & {{\text{for}}\;f\left( a \right) \le f\left( b \right)} \hfill \\ {P\left[ {f\left( a \right), f\left( b \right)} \right],} \hfill & {{\text{for}}\;f\left( a \right) > f\left( b \right)} \hfill \\ \end{array} } \right.$$

(1)

As illustrated, the most preferred function is 1 and the non-preferred function has a value equal to 0.

For the preferred functions to cover the preferential applications various shapes can be proposed e.g., linear, Gaussian, U-shape, and V-shape. Based on the form of the selected function, indifference threshold (q) and preference threshold (p) can be selected.

The index of the combined preference ($\pi$) for each substitute ‘a’ compared to the substitute ‘b’ can be presented as:

$$\pi \left(a,b\right)= \sum_{j=1}^{k}{w}_{j}{p}_{j}\left(a,b\right)$$

(2)

Here, ${\pi }_{j}\left(a,b\right)$ signifies the collective index for multi-criteria preference for (a) over the (b), ${w}_{j}$ represents the weight of the jth criterion, and ${p}_{j}(a,b)$ is the preference level of (a) over (b) concerning the jth criterion. The entering currents $({\varphi }^{-}(a))$ and leaving currents $({\varphi }^{+}(a))$ of ${a}_{i}$ are presented as:

$${\varphi }^{-}\left(a\right)=b \in k\pi (b,a)$$

(3)

$${\varphi }^{+}\left(a\right)= \sum_{b\in k}\pi (a,b)$$

(4)

The departure streams of an alternative (a) illustrate the inclination level for the mentioned alternative holds more appeals compared to others. The greater the departure streams become; the superior alternative will be. The incoming flows of alternatives (a) indicate the level of proficiency in comparison with other alternatives. The smaller values of departure streams are the improved alternatives. The obtained outranking streams can be computed⁴⁹:

$${\varphi }_{n}\left({A}_{i}\right)={\varphi }^{+}\left(a\right)-{\varphi }^{-}\left(a\right)$$

(5)

The ultimate preference of the obtained results on the calculated net flow is more promising.

Criteria for alternative energy resources

By considering the stated background on fossil fuel resources and the intended perspective on the future of the fuel of the vehicles, various alternatives can be taken into consideration. For this determination, the confirmed substitute fuels.

In this case, various types of energy resources i.e., CNG, LPG, Gasoline (Petroleum Diesel), Hydrogen, and Electricity can be taken into account. To elaborate on these fuels, different criteria are employed to evaluate their benefits and limitations more clearly. On this pathway, technical, economic, production expenditure, distribution charge, implementation costs, infrastructure accessibility, safety, policy, social, and environmental criteria can be used as potent tools for performance evaluation. Hence, each of the influential parameters in the decision-making process to select the most suitable fuels is reviewed. The employment of various criteria can ease the difficulties of comparison evaluations. Therefore, social, economic, policy and technical criteria are considered to put forward an appropriate decision-making process. Substitutes are scored by considering 3 technical sub-criteria, 2 economical sub-criteria, 2 social sub-criteria, and 3 policy sub-criteria.

It should be stated that policy plays a significant role in the considered decision-making process. The announcement of the framework of the standardized case, risk management, conventional alignment, strategies paths, available resources, and required guidance are the main concerns in the involvement of policy as a strong factor in the decision-making process. In a structured method, this factor can contain important parameters.

Economic

Economic parameters remain one of the key influential parameters in the decision-making method by providing a strong basis to evaluate the selected system's performance. Through these criteria, a proper comparison can be conducted between the fuels. One promising specification of the economic criterion is that this tool of measurement can be integrated into other criteria. In this case, production and distribution costs as well as implementation expenditures are involved to be assessed to provide a clear insight. Economic parameters can be effective in the short and long terms by investigating urbanization, climate change consequences, energy security, and limited oil resources⁵⁰. It is noteworthy to mention that the economy can be greatly affected by different parameters like internal rates of return, inflation rate, governmental subsidies, national taxes, etc. as may change the behavior of the projected outlook in a specific period. Moreover, the current types of ICVs have relatively lower costs than clean fuel-based vehicles or EVs. In the same vein, charges related to the production and employment of each fuel influence the overall price greatly, and afterward, the possibility of its application, as well as the degree of users’ acceptance. To elaborate on the operative factors in the economy, production, and distribution costs are elaborated. To a high extent, time developments and regional characteristics are important in the degree of production⁵¹. It has been shown that the erratic behaviors in the value of oil change the price of petroleum and substitute fuels. Conversely, costs associated with the implementation consist of the provision of a car driven by the selected fuels and related infrastructure charges⁵². Henceforth, investments and transitions to clean energies demand incentives from backbenchers and governments.

Technical

Technological advancements are a promising approach from a technical point of view. To assess the effects of the latest developments, a comparative investigation of the pros and cons of modern technologies respecting the typical and traditional facilities should be conducted. To get ahead in accomplishing the large-scale adjustment in this trend, the scientifically driven methods must be conducted by economic motivations and maintained by potent strategies. In this case, three sub-divisions can be taken to expand the area of investigation to deliver the advanced outcomes of the survey. In this case, infrastructure availability, energy content, and safety are the most important topics from a technical point of view.

The absence of appropriate infrastructure is a problem for the development of numerous novel technologies in the transportation division. To reduce the GHG releases to the environment, the infrastructure that provides these novel energy resources would be required to develop to deliver a great amount of energy to various users. An upgraded classification of the infrastructure obtainability for instance manufacturing technologies and refilling units would deliver the main influence on the upcoming efforts to commercialize the different types of energies⁵⁰. From the professional point of view, by considering the energy content, the superiorities of each introduced energy source as well as the advantages and drawbacks of the battery-powered systems can be observed⁵³.

One more point which believed to be pivotal is the fact that safety has been defined as one of the influential parameters in the technical criteria that play an unbreakable part in this area of expertise. To elaborate on this specific parameter, it should be mentioned that hazards and possible risks associated with the health and environment can be taken into consideration for further evaluation.

Social

Important concerns based on the social subjects can be addressed in this section. To be more precise, it is vital to mention the intended sub-categorizes as social acceptance and social welfare which are believed to be two potent symbols of social-related matters. One of the main downsides of the transportation systems is the GHG emissions to the environment which pulls the triggers for climate change, health problems, etc. that leads to social dissatisfaction. Initial statistics e.g., expert views, public attitudes, and insights are comprised of the planning and decision-making procedure in modern civilizations. Other points related to social acceptance can be introduced through the fees of fuel variations or imposed taxes over time which can be greatly effective⁵⁴.

Policy

GHG emissions and erratic behaviors of the oil price have provoked social discussions around the requirements of dealing with energy consumption through policy involvement. In detail, the inferior degree of consistency, which leans towards attributions of poor performance leads to the lack of reliability in policy structure or related implementations. Several aims that extend to numerous areas e.g., energy safety, environment, and fiscal progress are stated by legislators, causing the issue more probably to disturb; consequently, an upsurge in arrangement and consistency in objectives is extremely essential. Taking similar issues into consideration such as CO₂ production, energy safekeeping, and fuel trafficking, can help to upgrade the policy-related issues to the next level and link them to long- and short-term prospects^55,56.

Initial data and assumptions

To present the initial data more concisely, Table 1 provides the initial parameters to start the decision-making process. In this case, both measurable and immeasurable statistics have been considered in the assessment strategy. The entire data has been established regarding the evaluations by skilled scientists. Entire data for the alternatives are presented in Table 1. The criteria employed in this research encompass both quantitative and qualitative data. Professional experts have assessed and provided all the criteria data used in the evaluation approach. The performance values are stated by the professionals in that field by surveying.

Table 1 Obtained values for technical, economic, social, and policy criteria⁴⁹.

Assortment of skilled individuals is an important assessment process of Multi-criteria analysis (MCA)/multiple-criteria decision-making (MCDM) problems. The main specification of the substitute fuels’ evaluation issue deals with various features and is taken as an MCDM, which can principally be perceived in the assortment of criteria. To provide a trustworthy assessment, reliable specialists must consensus to handle each side of the obstacles. For this determination, a reliable source of data for further study is selected⁴⁹. The value attained for each alternative can obtain a score compared to the introduced criteria which can be computed as follows:

$${f}_{ij}=\frac{1}{N}\sum_{e=1}^{N}{u}_{eij} 1\le {u}_{e}\le 9$$

(6)

Here, ${u}_{eij}$ is the performance quantity based on the alternatives’ quality stated in the literature, e stands for the number of experts and referred literature, j represents the alternative to the criteria i, and N confirms the sum of advising experts or valid references. If ${u}_{ij}>{u}_{ik},$ the substitute j is assessed in a more efficient way than the substitute k based on criterion i, which is intended to be maximized or vice versa. Over the evaluation of this research, we have employed the obtained results from the research as cited in⁴⁹. It should be made crystal clear that in the referred research, the authors have put forward comprehensive research based on the obtained results from the officials, backbenchers, and governments. To put it simply, the investigation of this research is elaborated on their works by using their data and compiling the required data for the battery. It should be noted that the provided data for the criterion, the ref.⁴⁹ does not provide the associated data for gasoline and Li-Ion batteries. In this case, we have conducted the required investigation to find the required data by surveying the experts in these fields. In this way, we have interviewed professionals in the Meedco Company for Li-Ion battery and the National Iranian Oil Company for Li-Ion battery and gasoline data, respectively. In this way the provided ranking for the criterion details.

Each criterion's preference function has been defined independently in light of the decision-maker's preferences. Relating on the kind of assigned fondness function, either the fondness threshold (p), the indifferent threshold (q), or both are defined. Due to the nature of the data, a V-shaped function was constructed for the social criterion in this study and allocated to both the technical and cost-based criteria. Finally, a linear fondness function was used to process the data from the policy criterion. The p-value was set at 2 for all cost-based and technical sub-criteria excluding the energy content, while this item was regarded as 3 for the energy content sub-criteria. The p and q amount for each of the policy sub-criteria were set to 3 and 0.5, correspondingly. Table 2 presents all the criteria conditions.

Table 2 Initial considerations for involved criteria⁴⁹.

The relevance of one criterion concerning another is shown by the relative weights of the criteria. Each criterion can be applied at a regulated degree of relevance based on the viewpoint of backbenchers by giving it a variable weight. In this study, five alternative scenarios were created to examine the impact of the criteria's relative relevance on ranking from various angles.

The comparative weights of criteria specify the significance of one criterion in comparison with others. Allocating different weights to each criterion permits for controlled position regarding the decision-makers' standpoints. In the presented work, specialists determined the criteria weights for the base case, and five additional cases were shaped to observe how changing the qualified rank of the criteria changes the rankings from dissimilar views. In the basic scenario, the contributing shares of the criteria were determined by specialists. The social criterion had the lowest amount of importance in the base scenario, with a value of 10%, and the charge criterion had a considerable status with a worth of 45%. The weighted average for the technical and policy criteria was 10% and 30%, individually. In all cases, the general weight of each criterion was spread evenly across its sub-criteria. For example, the technical criterion has a weight of 15%, which equates to 5% for each of its three sub-criteria. The weight of each criterion in each scenario is displayed in Table 3. As can be observed, by changing the influence weight of each criterion, their impacts can be assessed. In this case, the share of each criterion increased considerably to show their impacts on the final obtained outcome (scenario II-V). However, in the first scenario, the considered share is equal to each other.

Table 3 Each scenario with the considered weights for associated criteria.

Results and discussions

By implementing the initial values in the considered methodology, the desired results are obtained to present a clear vision of the conducted comparison. It should be made quite clear that the implementation of the considered alternatives can be affected by the time procedure. In this case, two general scenarios have been introduced; short-term and long-term considerations. To elaborate on these scenarios, immediate implementation of the alternatives can be extremely harsh in the light of instant cost pressures as well as time-consuming procedures. Instead, to assess the long-term effects of the considered scenarios, the influential parameters have been taken into consideration.

Short-term evaluations

To start with, obtained results based on the PROMETHEE technique have been investigated. In this technique, the preferences of each parameter have been considered to provide a crystal-clear vision of the alternatives based on the initial data from Tables 2, 3 and 4. The initial stage which has been studied is the departure, inflowing, and net flows of all scenarios that have been presented in Table 4. With the help of Eqs. (1–4), the calculated values for the entering $\left( {\varphi^{ - } } \right)$, leaving $\left( {\varphi^{ + } } \right)$, net current $(\varphi_{n} )$, and associated ranks for each scenario have been presented. It is pervasive that for the base case scenario, based on the defined settings in the methodology section, the highest value of net current belongs to CNG which makes it an interesting option as the number one priority in comparison with other alternatives. As indicated earlier, in this scenario, the weights of the economic, policy, social, and technical parameters in the evaluation are 40, 30, 10, and 20%, respectively. In the same vein, gasoline, and LPG hold the second and third positions of the most preferred alternatives based on the introduced priorities. Meanwhile, biogas, batteries, and hydrogen are the least preferred alternatives, in descending order. As defined, the net value for the selected current, which is computed by leaving and entering streams, determines the rank of each introduced scenario. To elaborate on the other defined scenarios, other scenarios have been taken into the evaluations. For Scenario I, as the share of all design parameters is equal, the gasoline takes the first place while the CNG and LPG are in the next ranks of this scenario. As well, in this scenario, the least preferred fuels are battery and hydrogen. For Scenario II, while the share of the economic parameters carries on more weight (equal to 80%), the CNG, LPG, and Biogas are the most sought-after alternatives though the battery and hydrogen do not contribute a great deal in this evaluation as they both suffer from relatively high fees and associated charges. To elaborate the obtained results from Scenario III illustrated that gasoline and LPG are the most in-demand items as the share of technical parameters is equal to 50% and plays a significant role in this perspective. Likewise, the battery and hydrogen remained the least favored options in the short-term considerations. For Scenario IV, while the weight of the social parameter is a considerable term (50%), the CNG and diesel placed the first and second positions, respectively. Simultaneously, LPG and biogas are in the third and fourth ranks regarding their introduced design parameters. Similar to other scenarios, the battery and hydrogen are not favorable options as well. Ultimately, for Scenario V, the policy-based parameter carries more weight equal to 60% which leads to the way that makes diesel the most interesting fuel.

Table 4 Departure, inflowing, and net flows of all scenarios.

Obtained results from Table 4 reveal striking statics about the walking weights in different scenarios by considering the alternatives’ shares (Fig. 6). In this evaluation, if + 1 is considered the highest desirable, -1 is the least desirable alternative, and 0 is the neutral parameter based on the defined criteria. In this case, it is clear that for the higher values of the economic and social criteria, CNG turns out as the most desired alternative in comparison with other fuels while by increasing the technical weight in the calculations, the gasoline plays a crucial role in satisfying this need. For the cost-effective approaches, biogas and LPG are particularly better options in comparison with the other alternatives (e.g., battery, hydrogen, and diesel). One principally interesting fact emphasized by the figure is the fact that in the short-term objectives, battery and hydrogen have various challenges to face.

Fig. 6

Walking weights in different scenarios by considering the alternatives’ shares.

To examine the impacts of the criteria in the decision-making process, different approaches can be taken into consideration. On this path, GAIA permits the decision-making process to visualize the considered specifications of a decision problem. In this case, decision makers can effortlessly classify synergies or conflicts among the defined criteria, to recognize collections of measures and to highlight notable operations. Figure 7 demonstrates a visual image of this methodology to make it possible to assess the place of each alternative based on the defined criteria. As illustrated by the figure, the defined criteria are indicated by the colored lines as the positions of each alternative are determined based on the defined criteria. In this case, as shown in the figure, for none of the scenarios, battery and hydrogen do not follow the intended criteria in the optimized way while another alternative follows the criteria relatively while the defined weight for each one of the scenarios plays a crucial part in this section.

Fig. 7

GAIA-Brain schematic for the decision-making technique.

To present the effect of each criterion on the selected alternative, the GAIA Web of each alternative in the base case is presented in Fig. 8. In this case, as shown in the figure, the policy benefits are the most considerable plus point of the battery as the selected fuel while the economic outcomes show a lack of sufficient efficiency. In the same vein, the social and technical results are relatively medium in a comparative investigation.

Fig. 8

GAIA Web of each alternative in the base case.

Furthermore, to investigate the biogas performance, economic benefits play in a most significant way while other criteria contributed virtually the same. For the LPG, while the policy considerations are not fully satisfying, the technical, economic, and social parameters are promising and contribute to a similar share. For hydrogen, on the other hand, the most significant point that can be extracted is the fact that the policy criterion is enjoying a great deal of collaboration while economics stands as the least logical parameter among the defined criteria. For the CNG, the social benefits are the most important and noticeable criterion while contributing the most at its maximum value. In the same vein, the contributions of economic and technical parameters are almost equal while showing positive aspects in this way. The policy features stand as the least notable criterion. Lastly, gasoline has beneficial specifications from social and technical points of view. On the other hand, for this fuel, the policy-based decision has the minimum proportion of the overall total.

Visual stability intervals at the base case for the general criteria are a powerful tool to help the investigation of each criterion’s weight on the performance of the introduced alternatives (Fig. 9).

Fig. 9

Visual stability intervals at the base case for the general criteria.

As shown in the figure, increasing the economic share in the base case highlights the shortcomings in diesel, battery, and hydrogen from this point of view. This trend improves the priority of LPG, CNG, and biogas. Equally importantly, increasing the share of policy criteria will improve the favorability of battery and hydrogen though this modification will drop the values of other options. The reason for this adjustment is the fact that the share of economic benefits will be dropped to a great extent and mitigates its upcoming plus points. Another point that needs to be addressed is the circumstance that social criteria affect the alternatives in various ways. Although this change is optimistic for CNG and diesel, remains fully negative for biogas, LPG, and hydrogen. On another note, the effects of the variations of this criterion are neutral for the battery. Lastly, the changes in the value of the technical weight in the base case scenario are studied. It is clear from the static presented that increasing the technical weight will improve the performance of the gasoline massively. Moreover, this modification provides a positive outlook for the LPG and battery at insignificant rates. On the contrary, the increase in the technical weight will drop the attractiveness of CNG, biogas, and hydrogen, in the light of their performances.

Long-term evaluations

To investigate the effects of the decisions in the long term, this section is presented. To limit the assessments to a precise scope, in this section, gasoline and battery are compared in a long-run operation while the benefits and limitations of these adjustments are emphasized.

To commence with, the fuel consumption of the selected vehicles in general is compared. To elaborate on this matter, it should be noted that the typical gasoline consumption in existing vehicles (ICEVs) in Iran is 10 Lit per 100 km while the electricity power used for EVs is somewhere in the vicinity of 15 kWh for the same distance^57,58. To calculate the long-term effects of the electrification of available vehicles, a scenario is introduced in which the main assumptions are as follows:

• The targeted year for the study is the year 2040.

• The prediction is based on the estimations by ANN (Artificial Neutral Network).

• The government’s perspectives on CNG-powered vehicles are taken into consideration.

• The effects of employing conventional and modern gasoline-powered vehicles are studied separately.

• It is expected that 10% of the overall vehicles in Iran become EVs.

• The growth of electricity power and gasoline fees is studied over the considered years.

• The mean value for distance covered by vehicles in Iran is 18,000 km.

To start with, the considered assumptions are used to conduct a prediction on the long-term application of EVs in the transportation system of Iran from economic and technical points of view. As shown in Fig. 10, the number of ICEVs will undertake a period of erratic behavior for 16 years while experiencing lows equal to 11.48 million vehicles and highs equal to 13.18 million cars. Moreover, the number of ICEVs will reach 12.03 million in the last year (2040). On the other hand, the number of CNG vehicles will reach 10.399 million cars over the 16 period while the official legislators have conducted an optimistic outlook to increase the number of this specific type of car. Finally, the number of EVs will reach 10% of the overall production equal to 2.49 million vehicles. The overall trend of this group of cars remains highly upward during the selected period.

Fig. 10

The predicted number of different categories of vehicles counting ICEV, CNG, and EVs.

Another parameter that needs to be studied is the fuel fee that should be estimated over the considered period. As introduced earlier, there are two types of fuel; i.e., electricity and gasoline. By entering the policy-maker's decisions and social indexes, as well as the history of the fluctuations in the costs of these two fuels, the presented values are provided. In this case, in 2025 it is expected that these values reach 0.1 US$/liter for gasoline and 0.008 US$/kWh for electricity. It should be noted that by implementing the background statics and objected value for 2040 into the ANN, it is made quite clear that the charges for gasoline and electricity will reach 0.54 US$/lit and 0.1 US$/kWh, respectively.

By taking the data from Fig. 11 and initial assumptions as well as the fact that each car in Iran (on average) travels 18,000 km per year, Fig. 12 is presented. It is clear that, over the selected duration, the impacts of EV presence become more highlighted while their number increases considerably. By separating the ICEVs into two main categories based on the type of ICEV (conventional and modern), two different approaches are provided. In this case, if the EVs become produced over the period, the gasoline consumption will drop by diminishing its share in gasoline consumption and increments in electricity use. Moreover, by spreading the number of EVs, the electricity consumption by these types of vehicles becomes more and more gradual. The electricity use increases from 34.56 MWh to 6730.42 GWh. On the other hand, for the ICEV (conventional models) without considering the EVs, the gasoline consumption reaches 26.1 × 10⁹ L from 20.7 × 10⁹ L.

Fig. 11

The predicted charges for gasoline and electricity.

Fig. 12

The estimated fuel consumption by different category.

To investigate the influence of the considered approach for each scenario, the imposed charges for the fuels are calculated (Fig. 13). In this case, over the 16 years, the overall fees have been raised while this trend remained highly upward for ICEV (conventional models without considering the EVs) from 20.7 × 10⁸ US$ to 14.1 × 10⁹ US$. To elaborate on the costs associated with the electricity it should be noted that, over the inflations and growing use of electricity, the computed charge will increase from 2.76 × 10⁵ US$ to 67.3 × 10⁶ US$. Moreover, for the model types of the vehicles with lower fuel consumption, the overall charge for the scenario in which no EV vehicle is produced will reach 10.35 × 10⁶ US$ to 70.77 × 10⁶ US$ which stems from higher fuel consumption and the growing value of the gasoline fee. The trends for the options that provide details on the ICEV with EV presence are the same.

Fig. 13

The associated charges for each type of vehicle.

The last result that can be obtained from the technical and economic assessments is the gained benefits from the EV prevalence through the selected period (Fig. 14). This benefit is extractable through the lower consumption of gasoline in ICEVs. It is pervasive that the benefits of the EV’s presence as the alternative to the conventional models of the ICEV can provide growing interest in this outlook from 2.02 × 10⁶ US$ in 2025 to 17.55 × 10⁸ US$ in 2040. It should be expected that these profits can be more by providing more EVs in the transport services either transportation or private transportation systems.

Fig. 14

The overall benefits of employing EVs in comparison with conventional ICEVs.

The environmental benefits of using EVs in comparison with the ICEVs from CO₂, tailpipe emissions, lifecycle emissions, and battery manufacturing CO₂ can be tabulated in Table 5. The operational plan is until 2040. In this table, the number of ICEVs and EVs are the same and the EVs column declares the strategy for substitution for the ICEVs. As can be observed, around 40% of CO₂ is less produced in the EV strategy in comparison with the ICEV in annual operation. Moreover, the NOx and PM are neglectable in the EV plan while it is a considerable value for the ICEV plan. This finding confirms the environmental benefits of the EV strategy for annual performance.

Table 5 Environmental aspects of the EV compared to ICEVs in Iran for long-term plan.

Conclusion and policy implications

In this research, a comprehensive assessment of the alternative options for transportation systems’ fuels has been conducted. In this research, Iran is a developing country that is taken as the case study. In this case, LPG, Gasoline, Biogas, Hydrogen, CNG, and Li-Ion Battery are considered as the potential options for the dominating or contributing alternative in the transportation sector. To elaborate on the performance of each introduced alternative, two perspectives are considered; short-term and long-term evaluations. In the short outlook, six scenarios are introduced based on the technical, economic, social, and policy criteria and each scenario benefits from different weights. Instead, in the long-term study, the effects of electrification in Iran are studied. In this scheme, the impacts of evolutions in the battery applications in the vehicles are investigated. These considerations for the comparative study between fossil fuel and batteries have been carried out by considering the technical and economic parameters to provide insightful aspects of the intended study. Based on the short-term study, CNG and gasoline are considered the best options for the fuels of vehicles in Iran by taking into consideration the current situation. Regarding the economic, technical, social, and policy criteria, the short-term analyses are conducted. On the other hand, for the long-term investigations, the ANN was employed to predict the statics of the selected fuels in the near future. By considering the technical and economic criteria, it was concluded that the Li-Ion battery provides better performance in comparison with gasoline in the long run. Moreover, the obtained interest from this transition would be beyond the predictions. These benefits are extractable through the lower consumption of gasoline in ICEVs.

• It is pervasive that the benefits of the EV’s presence as the alternative to the conventional models of the ICEV can provide growing interest in this outlook from 2.02 × 10⁶ US$ in 2025 to 17.55 × 10⁸ US$ in 2040. It should be expected that these profits can be more by providing more EVs in the transport services either transportation or private transportation systems.

• Over the 16 years, the number of ICEVs will reach more than 12.03 million by 2040. Conversely, the number of CNG cars will reach 10.399 million vehicles over the 16 period while the lawmakers have directed a positive outlook to increase the quantity of this type of vehicle.

• By 2040, the number of EVs will reach 10% of the total car production. It is attained that the paybacks of the EV’s presence as the alternative to the internal combustion vehicles can provide growing interest in this outlook from 2.02 × 10⁶ US$ in 2025 to 17.55 × 10⁸ US$ in 2040.

• Furthermore, by increasing the number of EVs, the power used by these types grows into more and more value. The electricity consumption increases from 34.56 MWh to 6730.42 GWh.

• For Scenario I, gasoline is the main priority while CNG and LPG are in the next positions. Additionally, the least favored energy resources are batteries and hydrogen. For Scenario II, CNG, LPG, and Biogas are the most desirable substitutes.

• To elaborate the obtained results from Scenario III illustrated that gasoline and LPG are the most in-demand items as the share of technical parameters is equal to 50% and plays a noteworthy part in this perspective. Likewise, the battery and hydrogen remained the least favored options in the short-term considerations.

• For Scenario IV, the CNG and diesel placed the first and second positions, correspondingly. At the same time, LPG and biogas are in the third and fourth ranks regarding their introduced design parameters. Similar to other scenarios, the battery and hydrogen are not favorable options as well. Ultimately, for Scenario V, the policy-based parameter carries more weight equal to 60% which leads to the way that makes diesel the most interesting fuel. Nearly 40% less CO₂ is produced in the EV approach in comparison with the ICEV in annual operation. Moreover, the NOx and PM are neglectable in the EV plan while it is a considerable value for the ICEV plan.