Risk Assessment Framework for Electric Vehicle Charging Station Development in the United States as an Ancillary Service

Abstract

Promoting the accelerated adoption of electric vehicles (EVs) in the United States (US) is one of the main strategies for reducing risk related to climate change. However, the lack of public charging stations (EVCSs) in the US has been identified as a grave obstacle to EV market penetration. The US Federal Government is providing extensive financial incentives to promote EVCSs. This allows diverse businesses to offer EV charging as an ancillary service, without the risks associated with traditional fuel facilities. Locations offering these novel services will reduce their financial operational risks, increase customer traffic and receive additional revenue. However, selecting unsuitable equipment for particular business segments and locations creates a severe risk of underuse and disrepair, leading to the potential failure of these new projects. Furthermore, these unsuccessful EVCSs exacerbate consumer reluctance to EV adoption and foster social opposition to this new technology. This study provides stakeholders with a framework for the optimal placement of EVCSs to maximize their successful deployment and incentivize continuous growth in the EV market. It identifies risk factors related to the placement and operation of EVCSs, aiding in optimal equipment selection for each location. Results from this study highlight EVCS location trends based on location and type of business, with the potential for some retrofitting projects. This framework provides relevant geospatial results for business owners, policy makers, consumers and other stakeholders in the adequacy of new charging infrastructure.

1. Introduction

As the world experiences continuously intensifying extreme weather events, the urgency of tackling climate change has become one of the most pressing concerns for governments and societies globally [1,2]. Transportation is one of the main generators of greenhouse gases, and therefore the transition to electric vehicles (EVs) has been considered with great interest [3,4,5]. Through the Inflation Reduction Act, the United States (US) Federal Government committed billions of dollars to accelerating the transition to EVs [6]. It is expected that this investment will create the required momentum to accelerate EV adoption, allowing EVs to become the prevalent transportation mode in the near future [7,8]. However, several risk factors have been identified as consumer deterrents in this transition, with the following three causing the greatest concern: (1) the price of these vehicles, (2) range anxiety and (3) the lack of EV charging stations [9,10]. The challenges regarding the price of EVs have been addressed by manufacturing process improvement, technology integration, financial incentives and marketing projects [11]. The success of this strategy has created diverse EV models which are becoming competitive with traditional vehicles [12,13].

The remaining two challenges are intimately interlinked with the availability and adequacy of electric vehicle charging stations (EVCSs) [9,14,15]. Range anxiety relates to the availability of fast charging equipment on major roads to address the needs of long-distance drivers [9,16]. On the other hand, the lack of EVCSs affects populations residing in locations without home garages, such as apartments, with no access to private EVCSs [17,18,19]. EVCSs would need to be exponentially expanded in optimal locations to overcome these challenges [20,21]. Public locations require assessment and characterization related to the changing needs of consumers [20]. Therefore, the expansion of EVCSs at the national level is a complex undertaking, requiring the deployment of novel and diverse infrastructure network to support and promote EV growth [14,16,21]. Incentives and investments from federal, state and local governments will play a critical role in promoting this scheme, with the goal of establishing half a million EVCSs in the near future [22,23,24]. This will allow EV owners to have accessible and adequate charging capacity at home and on the road, with reasonable charging times [25,26].

However, the traditional paradigm of fuel recharging will be upended by this new technology. Historically, gas stations have been conceived as standalone businesses, due to the short times required to fill up the tank, allowing quick visits to adjacent businesses for bathroom breaks and shopping [27]. This model has been further reinforced considering that gas facilities present long-term environmental and financial risk, discouraging many businesses from participating in this sector. This risk derives from the underground storage tanks required for gasoline, dramatically increasing an organization’s risk of needing to pay maintenance and remediation costs [28,29]. Underground fuel tanks, regardless of their safety measures, have a very high probability of leakage in the median and long term [30,31]. Once soil has been polluted by fuel, the property owners are legally responsible for remediating and compensating for potential damage, including ground water infiltration. The cost of these risk liabilities can be significant [28,32]. Therefore, apart from some grocery stores offering fuel services in remote parking lot locations, the majority of businesses have opted out of offering these services due to their potential risk and liabilities [29,32,33]. Reports have indicated that in recent times, the number of traditional gas stations has been systematically decreasing all over the world, considering higher gas vehicular efficiencies, permit-related challenges and the liabilities and risks involved [25,34]. When compared with traditional gas stations, EVCSs generate no emissions or potential leaks, eliminating the risks for landowners and operators [29]. To minimize EVCS end-of-life risks, new industries are being developed with circular economy models, ensuring that this equipment is properly reused or recycled. This is of particular relevance, considering that the materials used in EVCSs are scarce and expensive, leading to the development of extensive life-cycle assessments to ensure a reduced risk for this novel infrastructure [35,36]. To further reduce electricity supply risks, renewable energy is being applied, integrating potential sustainable and reliable microgrids [37,38,39]. Currently, many organizations already offer ancillary non-competing products and services alongside their normal activities. Examples of ancillary products include auto repair shops and car washes in the parking lots of established business operations, food court operations and booths for hearing and eye examinations and medical aid product sales. Large retailers such as Costco, Sam’s Club and Walmart have been exploring these alternatives for the last two decades [40]. Therefore, the new EVCS model, which eliminates the risks of traditional fuel stations, will involve placement in locations with existing business activities. These ancillary services will contribute to additional revenue and customer traffic, while supporting the growth of the EV industry [27,41].

There are two types of EVCSs that may be installed, each with different charging times and price structures. Level 2 utilizes high-voltage connections and takes 4–10 h to charge 80% of an EV battery. Direct Current Fast Charging (DC Fast) is able to charge 80% of an EV battery in 20–60 min [42,43,44] and has the highest utilization cost [21,45]. Therefore, regardless of the EVCS type, there will be a longer wait time for EV charging when compared with traditional vehicle refueling. Having businesses attached to EVCSs, such as restaurants, shopping centers, or hotels, would allow customers to have a more convenient place to wait, while providing these locations with additional customer traffic [27,46]. Level 2 EVCSs would be adequate for businesses with longer customer visit times such as hotels or office buildings, while DC Fast would be ideal for shorter visits such as restaurants, convenience stores or shopping centers [44,47,48]. Placement of EVCSs in non-optimal locations may cause these facilities to remain sub-utilized or fall into disrepair, while other installations are oversaturated. Recent market reports indicate that in the US, at a national level, twenty percent of EV owners could not charge their car in a facility and left because of long lines or inoperable chargers [49]. This situation creates a decline in consumer satisfaction, increasing the risk of failure for EVCS infrastructure projects and EV market expansion, increasing social opposition to these projects [49,50,51,52].

This study provides a novel risk assessment framework for EVCS development, applying Geographic Information Systems (GISs) and data analytics. The fuel charging business paradigm is evolving as markets transition to EVs. Traditional gas stations will compete with many other business locations offering EVCSs. The granular data provided by this study will allow stakeholders to integrate a model for the optimal placement of an EVCS according to its charging characteristics, location and consumer patterns. The hypothesis of this study states that it is possible to develop a framework to guide stakeholders in the decision-making process for the type and placement of EVCSs depending on the required service level. The novelty of this study is the integration of reliable, diverse and large publicly available databases to identify the location of each currently installed EVCS. This integrated database will be incorporated into the framework, to which a GIS and BI are applied to provide stakeholders with guidance on the decision-making process for the future development of EVCS infrastructure across the US. This will maximize ancillary revenue from energy sales as well as improve customer traffic for adjacent businesses. Incorrect placement of EVCSs significantly increases the risk of failure for these new projects, causing financial losses, customer disappointment and community opposition. Therefore, this novel study provides a critical framework that minimizes risks related to the development of EVCSs. This framework was integrated with data for the United States but may be implemented in other locations with the inclusion of appropriate data.

2. Materials and Methods

This research applied a Geographic Information System (GIS) and business intelligence (BI) to develop a novel risk framework for the assessment and characterization of EVCS placement. Applying data for the United States, this study evaluated the growth of EVCSs as a critical factor in supporting the development of EV market penetration. Although sales of new EVs increased by 55% in 2022, comprising 8% of the sales for all light-duty vehicles [26], recent reports indicate that demand has fallen [10,53]. To forecast the growth of EVs in the near future and evaluate the support required from additional EVCS data for light-duty vehicles in the US, registration data from 2016 to 2022 were applied. Yearly data, segmented by vehicle type and US location, were obtained from the Alternative Fuels Data Center, US Department of Energy [54]. By applying BI and a GIS, the data were assessed, organized, homogenized, compiled and restructured to be applied in this framework. The location of EVCSs was evaluated and supplemented through GIS and BI approaches, applying geospatial data from Open Street Map data, Geofabrik, expanding location type for a substantial number of EVCSs [55,56]. Results from this GIS- and BI-implemented framework indicate that in 2022, more than 281 million light-duty vehicles were registered across the US, of which almost 2.5 million were EVs, which thus represent 0.9% of all registered vehicles [54]. However, as shown in Figure 1a, the geographical distribution of light-duty vehicles and EVs is not uniform. California is the state with the largest number of both types of vehicles, accounting for almost 13% of the nation’s light-duty vehicles and 37% of EVs registered in the US. The disparity in geospatial distribution is more pronounced in regard to EVs, as shown in Figure 1b. Regarding light-duty vehicles, they take up a share of almost 50% in 9 states and 80% in 22. On the other hand, three states have a proportion of EVs accounting for more than 50%, while this figure is 80% for twelve states. Therefore, when analyzing the present and future placement of EVCSs, it is critical to evaluate the current location of EVs and forecast their grow per individual geographical location. Data from federal, state and local agencies were applied in this study to perform assessment and forecasting of EVs and their infrastructure development. However, forecasts will depend on future market conditions, policy incentives, industry performance and technology developments. This framework aids stakeholders in optimizing EVCS placement and incentivize EV continuous growth, showcasing risks that may hinder this novel industry. For instance, previous research has indicated that the price of gasoline has a significant impact on the EV acquisition decision-making process, with higher prices increasing consumer awareness and EV market growth [57,58].

The location and characteristics of current EVCSs installed before the end of 2022 were assessed with data provided by the Alternative Fuels Data Center, US Department of Energy [59]. EVCS placement (Facility Type) was determined in this study, ascertaining optimal locations for each type of charging point. However, in the original database, less than 26% of records provided Facility Type information. This field was supplemented by data obtained through the application of GIS and BI methods to reach more than 90% of Facility Type identification. Text analysis for diverse fields on the database, such as Station Name or Access days, created complementary data that allowed us to ascertain the type of business area in the vicinity of the equipment. Additional supplementation was obtained from Open Street Map data, Geofabrik, allowing for the identification of location type for a significant number of EVCSs [55,56].

Criteria to ascertain the optimal placement of each EVCS included consumer category and activity, location type, travel characteristics (local commute or long distance) and acceptable waiting times, among other considerations. These factors were applied to assess the placement optimality of existing EVCSs for long-distance travel and for domestic usage. This study characterized charging points depending on their distance to the closest Alternative Fuel Corridor (AFC). Previous research has indicated that needing to travel additional distance is an important factor for customers when deciding where to refuel vehicles [60]. Businesses in the vicinity of highways can attract drivers to charge vehicles, as long as the access and distance are convenient. Some previous studies have indicated that businesses less than half a mile from the highway have the highest potential to draw customers [61], while other reports recommend distances as long as one mile [62]. This study applied a conservative approach, implementing a buffer of five hundred meters (approximately five blocks) alongside these roads with further characterizations every hundred meters (one-block segments) [62,63,64]. The designation of relevant highways as AFCs by the Federal Highway Administration (FHA), US Department of Transportation, is considered one of the main criteria in supporting the development of EV charging infrastructure [65,66]. This designation is currently interconnected with the Bipartisan Infrastructure Bill from the US Federal Government, providing funding for investment in this infrastructure project with the goal of transforming it into a reliable, affordable, convenient and equitable service for all EV users [66,67]. The FHA creates the designation based on yearly nominations from local and state officials and updates publicly available information for this denomination [66]. A GIS and BI were applied to overlay the EVCS type supplemented database, identifying locations in proximity of these major highways, considering the identified AFC 500 m buffer.

3. Results

Applying yearly data from the Alternative Fuels Data Center, US Department of Energy [54], related to light-duty vehicles registered per state in the period from 2016 to 2022, the EV growth rate per state was forecasted, as shown in Figure 2. The results shown in Figure 2a indicate that EVs will experience exponential growth and that by 2030, there will be more than 50 million EVs on the road, requiring an equivalent growth in the EVCS network to support and encourage this growth. The geographical distribution per state highlights that EVCSs will need to be placed throughout diverse locations, as shown in Figure 2b. California, for instance, will have more than 8.5 million EVs (17% of all EVs in US) by 2030, while Florida will reach more than 5 million (more than 10%). On the other hand, a significant number of states will have a much lower number of EVs, requiring the adjustment of the number of needed EVCSs.

Once EVs reach beyond 30–50% market penetration, it is expected that widespread adoption will evolve at a brisk pace. This will be fostered by supply chain maturity, EV financial benefits and the societal acceptance of this new technology. At current growth rates, considering yearly EV registration data for 2016–2022, the framework makes forecasts for state expansion, as shown in Figure 3. The maps indicate the forecasted year in which each state would reach 30% (Figure 3a) and 50% EV participation (Figure 3b), respectively. Only two states are projected to achieve 30% EV penetration by 2029, while one third of all states will achieve this goal by 2031. More than 70% of the states are estimated to achieve 30% EV registration by 2033, while almost 92% could reach this level by 2035. Furthermore, the forecast indicates that expansion to the 50% vehicular registration goal would be reached very promptly, with more than 81% of the states taking one year and the remaining locations two years.

However, EV adoption may slow down significantly if risks related to consumer concerns are not addressed. As previously indicated, two of the main barriers that hinder buyers’ plans to acquire an EV are range anxiety and public charging availability, both of which are significantly impacted by EVCS availability and adequacy. As shown in Figure 4a, Level 2 chargers had exponential growth until 2021, experiencing a reversal in 2022 with a decrease of almost 25%. This is concerning considering that these level connectors are required to support EV growth for consumers lacking private garage charging opportunities. On the other hand, DC Fast connectors have had irregular exponential growth over the last twelve years, with a reduced increase rate after 2020. This is likewise concerning, considering that these chargers are essential for long-distance travel and to ameliorate range anxiety concerns. However, as shown in Figure 4b, for both charger types, the overall trend forecast is exponential growth for the next ten years, reaching levels that can improve the availability of this critical infrastructure. As public and private funding continues to incentivize the growth of this critical infrastructure, the prospect of exponential growth, as projected in these results, presents a positive outlook. However, it is important to assess, characterize and optimize EVCS growth according to consumer needs and considering temporal and spatial criteria to minimize risks to this industry.

The ratio of light-duty EVs to public EVCSs is considered by the International Energy Agency (IEA) as a relevant factor in evaluating the availability of this critical infrastructure [68]. This ratio varies significantly across the world, considering that globally almost 1.8 million charging points have been deployed, of which 33% are fast chargers. The European Union set the target of 10 EVs for each charging point, with the intent of reducing this target in the future, to improve EVCS availability [69]. In the US, the ratio, at a national level and considering the data for registered vehicles and the number of available Level 2 and DC Fast connectors, is 16.98 EVs for each charger. However, further segmentation analysis is required to better assess and characterize EVCS availability. The results in Figure 5a show that DC Fast chargers represent only 20% of all charging points, which is concerning, considering their relevance for both consumers without home charging capabilities and long-distance travel. The need to increase the availability of DC Fast chargers in optimal locations should therefore be prioritized in the investment for this new infrastructure network. Figure 5b shows the current availability of EVCSs across the contiguous US, indicating that 18% of the states, accounting for more than 65% of all registered EVs, have a ratio of EVs to EVCSs higher than 20. Furthermore, 50% of the states, with 26% of all registered EVs, have an EVs-to-EVCSs ratio in the range of 10–20. Therefore, only 9% of all EVs (16 states) have an EVCS adequacy ratio equal to or lower than 10. This represents a very high risk for users regarding the availability of EVCSs and indicates a lack of adequacy for a large portion of EV owners. Furthermore, this reinforces negative perceptions for future owners, reducing their purchase intent for this new technology.

However, the lack of sufficient charging availability becomes even starker when the states’ EVCS ratios are analyzed considering the charger types. As shown in Figure 6a, the Level 2 EVCS availability ratio is lower than 10 for only 8% of EVs (13 states) as of 2022. On the other hand, 66% of all EVs have a Level 2 EVCS availability ratio higher than 20 (11 states). These results indicate that as the EV market expands, the EVCS availability could decrease if the charging infrastructure does not keep up with the required growth rate. This unbalance becomes even greater for the assessment of DC Fast chargers, as shown in Figure 6b. Seven states, accounting for almost 50% of all registered EVs, have an EVCS availability rate higher than 100. Furthermore, 58% of the states, containing 47% of all registered EVs, have an EVCS availability rate between 50 and 100, while only two states (0.06% of EVs) have a rate lower than 10. Considering that DC Fast chargers are critical for long-distance travel and users lacking domestic charging capabilities, these low availability rates could represent a serious setback for advancing EV market penetration. Current users are already expressing frustration both at the lack of available fast chargers and their inconvenient placement, creating negative societal perceptions of this new technology [70,71]. This consumer dissatisfaction can be directly linked to the low availability rate of EVCSs per state, which is exacerbated when considering that some of these facilities have improper placement.

Previous results indicate that improving consumer perceptions related to EVs to increase their market penetration will require significant investment in the EVCS network. The first goal is to increase the number of EVCSs per location to achieve an availability rate of 10 EVs per EVCS or better. Figure 7 indicates the number (in thousands) and growth rate (yearly % growth) of charging points required by 2030 to achieve a rate of 10. Results for EVs-to-EVCSs availability rate were calculated for the start of the year in which 30% target EV market penetration is predicted to be reached. As shown in Figure 7a, ten states will account for almost 52% of all EVCSs by 2030, with California, Texas and Florida taking the first three spots, with almost 28% of all charging points. Knowing the required growth rate for this infrastructure will be critical to ascertain the investment level required for each state. Results for this analysis are shown in Figure 7b, indicating that for the ten states with more than half of the EVCS inventory, seven will require an average yearly exponential growth of 50% or higher. Furthermore, 65% of the states, account for 66% of all EVs, will require a yearly growth rate higher than 50%, while one fifth will require a yearly average growth rate higher than 60%. This assessment is critical to better ascertain the investment requirement for each location to achieve the charging network growth required to support proper EV development, minimizing failure rates.

4. Discussion

Better characterization of the placement of EVCSs is critical to improving their utilization, profitability and overall success. As described in the Methods section, a 500 m buffer along the Alternative Fuel Corridor (AFC) was integrated to evaluate existing EVCSs. This will allow stakeholders to better identify users of this infrastructure. Charging facilities inside the AFC buffer will be a better fit for long-distance drivers, while the ones outside the AFC buffer could cater to local drivers. The results shown in Figure 8a clearly indicate a higher prevalence of DC Fast chargers in the AFC buffers along the AFC, with half of them inside the 500 m corridor and 36% within 300 m. On the other hand, for the Level 2 chargers, only 28% of the facilities are inside the AFC buffer, with 17% inside the 300 m. locations. These relevant results highlight that DC Fast chargers have been prioritized for long-distance travel. Although AFC buffer placement is important to support EV growth, the lack of fast charging infrastructure for local users may impact a large segment of EV users and impede this market’s expected accelerated development. The prioritizing of fast chargers for travel purposes is reinforced by the results shown in Figure 8b. Most states with small numbers of EVs and DC Fast chargers have a very high percentage of them in proximity to AFCs. States with a bigger EV inventory have a larger number of fast chargers in locations further away from AFCs, but additional strategies for risk reduction are required to serve domestic EV users.

Evaluating the growth trend of EVCSs since 2010 provides relevant insight into their potential future development and the challenges that this infrastructure may face in the goal of providing support for EV fleet expansion. As shown in Figure 9a, Level 2 chargers experienced a decrease in growth trend from 2021 to 2022, which, should it persist, may be concerning. Furthermore, Level 2 chargers located in the AFC buffer experienced a more pronounced decline than the locations outside the AFC buffer. The decrease for near AFC chargers was almost 72% from 2021 to 2022, which is significantly higher than the 23% decrease found for the points outside the AFC buffer. This may indicate a lack of investment in locations offering overnight stays close to AFCs, which may impact long-distance travel. On the other hand, DC Fast chargers experienced an upward trend for both AFC buffer locations, with the outside points experiencing a 29% increase from 2021, which is much higher than the 6% increase for the chargers inside the AFC buffer. Again, this analysis provides relevant insight into the importance of choosing the right placement locations to promote both EVCS and electric vehicle development. The assessment of the business type placement of existing chargers is presented in Figure 9b, segmented in accordance with the 500 m AFC buffer. Most of the business locations prioritize L2 chargers, which correlates with the expected parking time. Parking locations, offices, apartments and hospitals are the main locations of these chargers, catering mainly to local traffic, as represented by their lower concentration in the AFC buffer. Hotels prioritize L2 chargers, considering that most drivers will have overnight stays in these facilities. The proportion of hotels in the AFC buffer is higher when compared with parking facilities and offices, which indicates a stronger connection to long-distance travel. Although the number of DC Fast chargers is small for hotels, 74% of them are inside the AFC buffer, showcasing this sector’s strong reliance on long-distance travel. For shopping centers, the number of DC Fast chargers is higher than the number of L2 chargers, with 48% inside the AFC buffer. This indicates that these facilities have identified the needs of their customers with regard to charging options as well as the potential to attract shoppers on long-distance travels. Results from these analyses provide insight into the development of both charger types.

As previously indicated, the traditional paradigm for vehicle refueling at gas stations is changing. EVCS development as an ancillary service is attractive due to its lower operational and maintenance risks when compared with gas pumps and its potential to provide additional revenue. However, installing the right charger type for each location is critical for the success of these new investments and the overall growth of the EV industry. Level 2 chargers, which charge 80% of an EV battery in 4–10 h, are ideal for longer parking stays [72], as shown in Figure 10. Office buildings and apartments have a higher presence of L2 chargers with minimal DC Fast charging equipment. For office buildings, as reflected in Figure 10a, there was exponential growth until 2021, with a significant drop in 2022. EVCSs at office buildings are normally used during the day over regular working hours, preventing the use of electricity at peak consumption times. The results indicate that these stations are mostly geared towards local users, potentially benefiting workers without home charging capabilities. The 2022 drop is concerning considering the relevance of the market segment being served by these EVCSs. Further incentives and investment should be targeted towards these locations. On the other hand, Figure 10b shows the growth of EVCSs at apartments, serving the population that lacks a garage and are unable to install their own chargers. Considering that this is one of the market segments that has higher concerns about EV acquisition due to the lack of chargers, particular attention should be paid to these locations. The results indicate that these facilities are mostly outside AFC buffers, serving local populations, and show continuous exponential growth, without the 2022 reversal observed for other locations. This highlights the relevance of serving this market segment, promoting EV development among consumers living in apartments. These results are in line with and have similar trends to previous findings focused on California [73,74]. Furthermore, as indicated, the price of gasoline in each particular location could have an impact on consumer awareness and EV market growth [58,75].

On the other hand, the results presented in Figure 11 identify locations that are a good fit for DC Fast charger placement. For both convenience stores and gas stations, customers’ expectation is to have a shorter visit [76,77,78], which is a good fit for equipment that is able to charge 80% of an EV battery in as little as 20 min. At both locations, customers will have the opportunity for bathroom breaks and shopping or eating while waiting, which is ideal for long-distance travel (inside the AFC buffer), as shown in Figure 11b. The results shown in this figure highlight the exponential growth expected for fast chargers close to the main highways (the AFC buffer). Convenience stores, as shown in Figure 11a, have generated significant growth in serving local drivers (outside the AFC buffer) in the last three years, while long-distance travel has remained stable. Level 2 chargers for all of these locations have a very low presence, with gas stations showing a steep decline in these slower chargers inside the AFC buffer, indicating a lack of fitness. The risk of installing incorrect charger types in these locations may cause project failures. This highlights the relevance of promoting investments with market compatibility for each location and business segment to reduce the risk of failure.

Shopping centers and grocery stores are prime locations for EVCSs as an ancillary service to their customers, representing almost 13% of all charging point locations in the US. Furthermore, these locations represent 36% of all DC Fast charging points in the US and almost 39% of all fast chargers outside the AFC buffer. Figure 12a shows a decline for all categories from 2021 to 2022, with the exception of fast chargers geared towards local users (outside the AFC buffer). This indicates the importance that operators of these shopping locations are placing on providing customers with faster charging facilities in recent years. Almost 53% of charging points in shopping centers are DC Fast chargers, with this significant growth taking place in the last four years. Therefore, providing additional fast charging facilities in shopping locations will provide customers with adequate-level service, reducing investment risks for these projects. On the other hand, grocery stores, as shown in Figure 12b, have higher growth for both charger types outside the AFC buffer, catering to local users. It is noteworthy that grocery stores offer a mixture of both chargers, potentially serving two market segments which have different requirements and diverse parking times. Additionally, the growth in fast chargers inside the AFC buffer indicates that grocery stores in close proximity to roads may be a good stopping point to recharge during long-distance travel.

Level 2 chargers comprise 89% of all charging points in hotels, potentially representing the best option for guests staying overnight. As shown in Figure 13a, for the previous 3 years, there has been significant growth for Level 2 chargers, after a sharp decline in 2019. Fast chargers have experienced a small increase in the last two years for locations closer to AFCs, indicating that they can serve long-distance travelers making shorter stops. Hotels outside the AFC buffer have seen a more significant increase in Level 2 chargers, indicating that there is opportunity to increase the number of EVCSs that serve not only long-distance drivers but local visitors as well. Restaurants, on the other hand, experienced a very uneven development over the last seven years, as shown in Figure 13b. A total of 40% of charging points in restaurants are DC Fast charges, with 57% of them being installed in the last three years, showcasing a significant trend of installing fast chargers in these locations. However, Level 2 chargers have also seen a significant increase in recent years, creating uncertainty as to which is the most adequate charger type for these businesses. Additional granular analysis will be needed to aid in deciding which EVCS type should be installed for each restaurant location. The frequency of visits and EV driver types will help stakeholders in making decisions on the facility placement and layout.

Other locations, such as car dealerships and hospitals, have also experienced significant growth in EVCSs in recent years. Car dealerships and hospitals account for almost 7% of all charging points in the US, 90% of which are Level 2 chargers. Based on the growth patterns shown in Figure 14, these locations will play a relevant part in supporting EV adoption. Car dealerships appear to be one of the prime locations for EVCS development. However, the years following 2013 saw a lack of growth in these facilities, as shown in Figure 14a, potentially related to the slow development of EV production by many car manufacturers. The increase in EVSCs in these locations in recent years has been impressive, especially for the Level 2 chargers, supporting the EV vehicular inventory, with additional significant development of fast chargers outside the AFC buffer since 2021. As more companies develop and promote their EV models, the increase in EVCSs at car dealerships will experience exponential growth. Another emerging location for EVCS development is hospitals, as shown in Figure 14b. From 2019 to 2021, Level 2 chargers had exponential growth with a reversal in the 2021–2022 period, similar to the decreases experienced by many other locations. However, this yearly decrease was less pronounced than for other business segments. These assessments will aid hospital stakeholders in their decision to install EVCSs for the use of their patients and employees. By selecting the most adequate equipment, the risk of failure for the project will be significantly decreased.

5. Conclusions

Consumer concern about the lack of adequate public EVCS infrastructure is among the most critical risk factors for electric vehicle market penetration. This may reduce future sales and prevent the US from reaching its goals on greenhouse emission reduction. Therefore, developing a framework to allow for the accelerated growth of EVCSs with optimal placement is of paramount importance. Charging facilities in non-optimal locations have low utilization rates and fall into disrepair, while other locations may be insufficient to service all potential users. As EVCSs continue to be developed as ancillary services for existing business, it is imperative that stakeholders have a clear understanding of the framework to allow diverse charger types and locations to be successful.

An initial assessment and characterization indicated that the forecasted growth of EVs all across the US will be exponential. However, this growth will be uneven, with different US states showing different increase rates. Therefore, this study provides a geospatial framework for local EV development and corresponding EVCS investment, tailored according to their spatiotemporal growth. Achieving a rate of 10 EVs for each EVCS or better is considered as a minimum requirement to ensure proper charging availability and dispelling consumer concerns about the lack of this infrastructure. Results from the study indicate that each state will require different EVCS development rates to avoid the risk associated with a lack of proper charging facilities.

EVCS development is changing the paradigm of vehicle refueling. Most EV charging will occur in locations offering it as an ancillary service, with a significant reduction in the role of traditional gas stations. However, considering the two types of EVCSs most frequently used, ensuring equipment selection lines up with preferred consumer charging times and price ranges will be critical. Level 2 equipment would be adequate for long parking periods, providing a lower charging cost, while faster options can serve drivers making shorter stops at a higher cost. Long-distance travel and local charging are distinguished in this study through the Alternative Fuel Corridor (AFC) buffer defined by the Federal Highway Administration. Performing GIS and BI analysis for every business segment and AFC buffer location allowed this framework to identify diverse useful trends for the development of EVCSs according to their type. Some locations were identified as being preferred for the placement of fast charging facilities, while others would be optimal for slower charging, at lower prices.

The framework presented in this study aims to provide stakeholders with relevant information for the proper placement and selection of EVCS type. This will allow the development of a robust infrastructure network to support the growth of the EV industry. Future research will integrate granular analysis configured with location data of potential business segments that may be a good fit for EVCS placement. This will aid stakeholders in developing the most optimal charging infrastructure, so as to simultaneously support EV development and provide benefits for local business with these ancillary services.