With increased social interest in the environment, more attention is being paid to the transportation sector, which is considered a key contributor to greenhouse gas (GHG) emissions. The International Energy Agency (2017) indicated that about 14% of GHGs were generated globally by the transportation sector [1
], and this rate is estimated to increase to half of all GHG emissions by 2030. Therefore, several nations are attempting to reduce GHG emissions and environmental pollution by the transportation sector by decreasing the use of fossil fuels. Among several alternatives, electric vehicles (EVs) are regarded as one of the most promising approaches in the transportation sector [2
]. The U.S. National Resources Defense Council (2007) found that EVs can contribute toward handling several environmental problems [3
]. With this positive effect in mind, the majority of vehicle manufacturing companies are developing, introducing, and selling EVs [4
The energy demand of the world continues to grow [1
], and currently, more than 25 billion tons of CO2
arising from human activities are annually released worldwide into the atmosphere. Now, it is a world problem to reduce the emissions of greenhouse gases and air pollutants such as CO, HC, and NOx
by road transportations for city governance, as highlighted by previous studies (e.g., [5
]). In the meantime, South Korea, which has ranked 11th worldwide in terms of gross domestic product (GDP) in 2017 and is the world’s third fastest growing country in CO2
emissions, has signed the Paris Agreement on 2016, and its Intended Nationally Determined Contribution (INDC) proposes an economy-wide target to reduce GHG emissions by 37% by 2030 relative to the business-as-usual level [8
]. According to several prior studies [9
], the level of GHG emissions in South Korea has been 0.69 billion tons of CO2
in 2015, while a total of 49 billion tons of CO2
has been emitted globally in 2015. Moreover, South Korea has established a GHG reduction target of 34.3% to transportation as energy consumption by nonindustrial sectors such as transportation is expected to continuously increase [10
], and the South Korean Government is pushing the uptake of EVs with a goal of having 250,000 EVs on the road by 2020 [11
Nations worldwide are vigorously developing and discovering alternative fuel sources and new technology to lessen the dependency on fossil fuels because of the increasing energy demand, the uncertainty of fuel prices, and severe air pollution restrictions in the road transport sector. Furthermore, attention has been recently drawn to developing cleaner alternative fuels from renewable sources and to improving hybrid vehicles so that the harmful emissions to air in city centers and the need for fossil fuels can be reduced [5
In spite of this trend and its advantages, prior studies have identified notable barriers to the wide diffusion of EVs [2
]. For instance, Axsen, Kurani, and Burke [13
] found that the cost of a vehicle battery is a significant barrier to EV acceptance. Limitations in battery capacity and vehicle weight are further obstacles to commercializing EVs [14
]. This context has directed the focus of engineers and researchers in the field to technical issues, which has yielded improvements in terms of the engineering-related agenda based on what prior studies highlighted as the major restrictions on the spread of EVs [15
These improvements to the engineering and technical aspects of EVs have increased the importance of focusing on the users’ perspectives on these vehicles [16
]. EVs have been rapidly diffused in several developed countries, including Japan [17
], the Netherlands, and the US, whereas in some nations, such as South Korea and China, they have propagated slowly [19
Thus, the current study aims to explore drivers’ perceptions of EVs by examining the vehicles’ characteristics based on a model represented in user-oriented studies: the technology acceptance model (TAM) [21
]. This study proposes a new adoption model that can be applied to renewable energy technologies and vehicle systems to elucidate drivers’ acceptance of EVs in South Korea [19
]. This study addresses two research questions: (A) what driver-oriented variables motivate intentions to use EVs? And (B) can the original TAM validly be applied to EVs?
The remainder of this paper is structured as follows. First, a literature review is presented. Second, the hypotheses and research model are introduced. Third, the study methods are elucidated, and the results are presented. Finally, a discussion, conclusions, and the limitations of the study are provided.
Although automobiles based on the internal combustion engine are popular in our society, EVs has also been invented in the early stage of automobile history. However, vehicles installed with internal combustion engines have dominated the market, primarily against a background of widely available oil at low prices. Since the 1990s, with the increased interest in environmental issues, including GHG emissions, a number of nations and manufacturers have started paying more attention to EVs and hybrid EVs [23
]. A hybrid EV has both an internal combustion engine powered by fossil fuels and an electric motor powered by a battery [25
]. The battery is charged by the internal combustion engine when the vehicle is braked. Because the original energy of hybrids is supplied by fossil fuels, they are more economical and efficient than traditional vehicles [26
Generally, EVs are referred to as battery-electric vehicles. Battery-electric vehicles are powered by large battery packs that are recharged via the electricity supply [27
]. Although the widespread distribution of battery-electric vehicles may be the most promising solution for future transportation systems, the mass distribution of battery-electric vehicles is more difficult than that of other vehicles, including traditional ones, because of several limitations and technological differences [28
Public attitudes toward EVs and public willingness to use them should be considered in promoting the use of these vehicles in the transportation sector. Not only should the technical limitations of EVs, including battery capacity and weight, be improved, but also drivers’ individual and social issues should be investigated to enhance commercially successful distributions. Prior studies have reported that users’ adoption and preferences are important factors for successful maintenance in the transportation sector [29
]. Thus, this study investigates users’ perceptions of EVs through the introduction of a new integrated model of EVs adoption.
4. Discussion & Conclusions
The purpose of this study was to explore drivers’ motivations for using EVs. We conducted a structural investigation by examining and exploring a driver acceptance model. Based on one of the most widely employed user-oriented models, the statistical results indicated that the original TAM is valid for elucidating driver acceptance of EVs, and a sequential structural relationship of perceived enjoyment—satisfaction—attitude—intention is supported for explaining acceptance.
Building on the findings of prior studies that utility- and price-related factors are the key motivations for using renewable energy technologies and products [53
], this study showed that users’ satisfaction and enjoyment should also be considered in explaining their behavior and willingness to use such technologies and products.
This study introduced a new adoption framework for elucidating the user-decision process for EVs. Moreover, the integrated adoption framework was investigated by using SEM to explore the motivations for users’ intention to use EVs and the systematic decision process. The results supported the validity of the proposed model, which thus improves our understanding of users’ willingness to use and perceptions of EVs.
Similar to prior TAM studies, this study confirmed the validity of the model in explaining users’ perceptions of EVs. In addition, the integrated model and results mirrored the current status of EVs: (A) drivers consider their experiences with an overall feeling of enjoyment and satisfaction with the vehicles (0.173 and 0.423); (B) drivers’ expectations of cost, including the cost of maintenance and purchase, can disturb their intention to use the vehicles (−0.378); and (C) drivers’ perspectives toward the hedonic, utilitarian, and economic aspects of EVs should be considered in attempts to diffuse the vehicles. Thus, these factors should be considered when academic and industrial researchers and politicians want to promote EVs. The motivations of drivers, such as intention to use, perceived usefulness (0.366), and attitude (0.261) as positive determinants, and perceived cost (−0.378) as a negative one, were investigated as the key factors in encouraging drivers to purchase and use EVs and establishing support facilities.
The results of this study have several industrial and academic implications related to EVs for engineers, researchers, and government officers, including policymakers. From a practical perspective, practical engineers and researchers can apply our results to enhance EVs by improving their degree of utility and increasing users’ hedonic perceptions of the vehicles. Moreover, government officers, including policymakers, should design financial and supportive policy plans minimizing the cost aspects of EVs for potential drivers. Moreover, automobile manufacturers should establish systematic and user-oriented plans to improve users’ overall satisfaction in using EVs. With the increasing environmental concerns in our society, well-designed plans could encourage potential drivers to consider EVs for transportation. That is, future plans should be established with the considerations of not only economic aspects of EVs, but also users’ experience of EVs. For example, the UK government operates the integrated supporting plans and provides the incentives of 35%-purchasing price (up to £4500) for low-emission vehicles based on seven categories [54
]. The supporting plan in Norway mainly concentrates on tax benefit, including no purchase/import taxes, no charges on toll gates, half-company automobile tax, and so on [55
]. However, in South Korea, there are two separated supporting plans for EVs which are operated by the central and local governments, respectively [56
Academically and theoretically, this study improves our understanding of this conceptual structure, including utilitarian, hedonic, and economic factors and their connections. Considering the prior studies that explored drivers’ perceptions of alternative transportation including EVs [57
], the research model suggested and verified by this study can be applied to increase our overall understanding of drivers’ adoption of EVs. Although this study examined users’ adoption decisions related to EVs as a future transportation method, the following two research questions remain: (A) are other aspects of EVs significantly related to users’ adoption of the vehicles? And (B) can the adoption model proposed by this study be used to explain future transportation methods and renewable energy products?
This study attempts to expand the findings of previous technology acceptance studies on users’ adoption of particular technologies and products. Therefore, it contributes to the literature on EVs and renewable energy products by investigating the core roles of the variables examined and their significant connections in the integrated research model.
This study has several limitations. First, other factors may be significantly associated with users’ intention to use technology. For example, prior studies on user behavior have indicated that personal characteristics of users and the technological factors of particular products and technologies can be strongly related to users’ perceptions of those technologies and products [58
Second, some relationships may have been missed in the proposed research model. The correlation values among several of the investigated factors were high. This study has used a condensed model that excluded complicated connections.
Third, this study does not consider the unique characteristics of the individual driving experience. As previous studies have indicated, the driving patterns of EVs can be significantly affected by charging and parking systems [43
]. Moreover, drivers’ subjective needs and targeting behaviors can be related to their perceived usefulness [59
]. Moreover, prior studies have showed that infrastructure availability for a particular service is strongly associated with users’ perceived ease of use [60
Fourth, although the functionality and usability of EVs have been extracted via the initial interview, perceived risks and problems in terms of the technical aspects of EVs have not been considered while prior studies have showed that the environmental aspects of EVs can be significantly related to users’ attitudes toward them [59
Fifth, there may be a common method bias. Several prior studies on SEM and information systems have shown that this bias can significantly influence the results of SEM and regression analysis [62
]. Considering previous studies on how the perceived risks of renewable energy facilities and products affect their distribution [44
], future studies should extend the research model by examining the potential risks and problems of EVs.
Sixth, perceived enjoyment of EVs has been one of the motivators for boosting driver attitudes and increasing their intention to use through perceived satisfaction. Therefore, future research should examine the relationships between perceived enjoyment of EVs and driver perspectives toward them.
Due to these limitations, future researchers should be careful in applying the results of this study to explaining other future transportation and renewable energy products.