Emerging Technologies in Transportation Casebook/EV Charging

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EV Charging[edit | edit source]

This casebook reviews Electric Vehicle Charging. It is the collaborative work of George Lu, Melanie Weiland and Eyan Bantebya, graduate students enrolled in George Mason University at the time of writing. It was produced as an assignment for George Mason University's Emerging Tech, Transportation & Public Policy graduate course, taught by Dr. Jonathan Gifford.

Introduction[edit | edit source]

Since the industrialized mass-production of vehicles, crude oil has been the primary source of fuel for urban transportation. Crude oil is produced on a global scale and has maintained the cost of transportation at an economically affordable rate. However, the advantage of crude oil has declined due to the increase in oil price and increased awareness of the adverse environmental consequences of consuming fossil-based fuels. To address the issues, the transportation systems are evolving to a more economically and environmentally sustainable situation. Electric transportation systems are emerging as an attractive and viable solution.

Sales of new light-duty plug-in electric vehicles, including all-electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs), nearly doubled from 308,000 in 2020 to 608,000 in 2021. EV sales accounted for 73% of all plug-in electric vehicle (EPV) sales in 2021. EV sales grew by 85% from 2020 to 2021, while sales of PHEVs more than doubled, with an increase of 138% over the previous year. The rapid growth in plug-in electric vehicle sales from 2020 to 2021 is remarkable in the context of overall light-duty vehicle sales, which increased by only 3% during the same period[1]. (Energy Saver, 2022)

Federal acquisitions of EVs and the number of charging stations are increasing. The U.S. government owns more than 650,000 vehicles and purchases about 50,000 vehicles annually. In 2020, less than 1% of new federal acquisitions were electric, which more than doubled in 2021 and in 2022 agencies have acquired five times as many EVs as all of last fiscal year. Biden signed an executive order in December 2021 directing the government to purchase nearly all EV or plug-in hybrid electric models by 2027. As a lack of charging stations remains a key hurdle to wider EV adoption, congress approved nearly $5 billion over five years to give grants to states to build thousands of electric vehicle charging stations. On September 14, 2022. the US government President Joe Biden announced the approval of the first $900 million in U.S. funding to build EV charging stations in 35 states as part of a $1 trillion infrastructure law approved in November 2021. By 2030, Biden wants 50% of all new vehicles sold to be electric or plug-in hybrid electric models and 500,000 new EV charging stations[2]. (Reuter, 2022)

Despite the rapid growth of PEV, a number of barriers still exist, such as high purchasing cost, limited driving range per charge, long charging time and lack of charging infrastructures. Among the barriers, the underdevelopment of fast charging infrastructures, particularly fast charging infrastructures, is the most significant barrier for accelerating EV’s penetration.[3] (Zhang, 2018)

Profit of Public Charging Infrastructure[edit | edit source]

In general, the profit of a public charging station can be expressed as income minutes investment and cost of Operation and Maintenance (O&M).

Profit = Income - Investment - O & M

The Income mainly comes from the fee charged to customers. In addition, governments can also provide economic support, such as subsidies, to promote the development of public charging stations. The subsidy can be provided for both construction and operation of public charging infrastructures.

The Investment usually covers the capital needed for building the charging stations and the costs of charging units.  

The O&M costs are to cover the daily operation and maintenance costs such as electricity bill, the rent of ground, and maintenance of the ground surface and charging units etc. (Zhang, 2018)  

Key Factors Affecting the Development of Charging Infrastructure[edit | edit source]

Charging Demand[edit | edit source]

The number of PEVs is the most important factor that decides the charging demand and thus affects the profitability. Increasing the number of PEVs, in general, would have positive influences on the profit since more PEVs usually lead to a higher charging demand (Schroeder and Traber, 2012). The location of charging infrastructures can also have a great influence on the charging demand. The demand in urban areas is higher than in the rural areas[4]. (Wirges, 2012)

Charging Price[edit | edit source]

The charging price and the capacity are two main decisional factors for the charging infrastructure operators. They have an intricate relationship with charging demand and the cost for charging infrastructures. Currently, the operators mainly make profits from the price margin of electricity as well as the government subsidy on charging infrastructures. The decision of charging price is an issue that the operator should strike a balance between profit of charging stations and charging demand from EV users[5]. (Schroeder, 2010) The charging price will also influence the expense of PEVs, and thus impact the number of PEVs.

Government Influences[edit | edit source]

The number of PEVs could influence government policies on charging infrastructure since government policies should take into account the status of the PEV market. Government can promulgate regulations and action plans on the construction and operation of charging infrastructures, in order to accelerate the investment in an area. (Yang, 2016)

Skerlos and Winebrake (2010) reviewed public policies for EV penetration in the United States and suggested that a differentiated subsidy scheme for EVs can increase EV penetration, charging infrastructure construction and social welfare.

Funding in the Infrastructure Investment Jobs Act (IIJA)[edit | edit source]

While there are many funding opportunities in the IIJA, the National Electric Vehicle Infrastructure Formula Program (NEVI Formula or NEVI), provides a significant $5 billion in funding available over 5 years to the states to establish national charging infrastructure across the U.S.

The funding is allocated through the Federal Highway Administration (FHWA). Initial program guidance issues by the FHWA at the beginning of this year required that each charging station included at least four 150 kW Direct Current Fast Chargers capable of charging four EVs at once by a 97 percent uptime on operability. Additionally, the guidance also designated the chargers to be placed along alternative fuel corridors and states should prioritize investments along the interstate highway system. Additionally, the guidance prohibits funding from going towards charging systems with proprietary charging systems.

Currently, all 50 states have submitted their initial plans for how to deploy their allocated NEVI funding and the FHWA has accepted all plans on September 27, 2022.

Density of Charging Units[edit | edit source]

Wirges et al. (2012) pointed out geographical density of charging infrastructures can affect demands of charging. When the density of charging infrastructure is high, it is hard to stay profitable. Too many charging stations in an urban area can lead to under-utilization of the charging stations and the stations cannot be operated economically. Dispersion of charging stations over rural areas would also help to alleviate the range anxiety of PEV customers.

Unit Construction Cost of Charging Units[edit | edit source]

Less unit construction cost of charging units will encourage more investments on charging infrastructures. With spending less capital on the investment, investors can anticipate more profits for return, or reduce charging prices to attract more customers.

Ground Rent and O&M Costs[edit | edit source]

The location of charging infrastructures could also influence O&M costs, which will further influence the charging prices. O&M costs are largely determined by the ground rent. The ground rent would be much higher in popular urban areas than rural areas.

Current Levels of EV Charging[edit | edit source]

Level 1 - Charges roughly 3 - 5 miles of EV range per hour and provides between 1.3 kW to 2.4 kW of power per hour. Can take over 24 hours for an empty EV battery to fully charge on a level 1 charger, however, can be a convenient option for residential spaces. Level 1 chargers are included in the purchase of an EV and are powered through an alternating current (AC).

Level 2 - Charges roughly 18 - 28 miles of EV range per hour and provides between 3 kW to 19 kW of power. Level 2 chargers are the most common form of charger for commercial spaces and are often preferred for residential areas. Require dedicated infrastructure in place to comply with the National Electric Code requirements and also powered through an alternating current (AC).

Level 3 - Unlike Level 1 and Level 2 charging, level 3 chargers are powered by a direct current (DC). DC fast charging and provide between 100 to 200 + miles of range per 30 minutes of charging. Chargers alternate between 150 kW to 350 kW of charging per hour. The max charge rate is often limited by the EV acceptance rate. Due to regulations and compliance issues, DC fast chargers are limited to commercial or industrial locations. They are most commonly found on highways or locations frequently traveled for long distance trips.

Charging Standards[edit | edit source]

SAE J1772[edit | edit source]

This connector is the Society of Automotive Engineers standard for all Level 1 and Level 2 EV chargers.

CHAdeMO[edit | edit source]

One of the earliest forms of EV chargers deployed and developed in a joint effort among Japanese automakers. As a result, this form of charger is still commonly used among Japanese automakers and their vehicles.[6]

Combined Charging System (CCS)[edit | edit source]

The combined charging system (CCS) was introduced after CHAdeMO. Unlike CHAdeMO, CCS allows for both alternating current and direct current charging at the same port. This connector is the preferred system for both European and American automakers and has quickly become an industry standard.[6]

Tesla Supercharger[edit | edit source]

Unlike CHAdeMO and CCS, Tesla’s supercharger works exclusively with their own vehicles. For many years, their proprietary connector would not work with any other system. Recently, Tesla stated that it would open up its network to other EVs, however, this is still pending. Yet, despite its exclusive system, the Tesla Supercharger was vastly deployed and offers over 35,000 chargers across the globe.[7]

Government Standards[edit | edit source]

As part of the Infrastructure Investment and Jobs Act, the Biden administration issued a Notice of Proposed Rulemaking that would require a new standard for EV charging stations with its deployment of EV charging stations through the National Electric Vehicle Infrastructure Formula Program. This standard would require any federal funding to use the combined charging system (CCS) and include adapters for all makes and models of EVs.[8]

Wireless Charging Technology[edit | edit source]

Aside from the slow charging speeds of electric vehicles compared to filling up a tank of gas is the availability of charging stations. Even as the popularity of Electric vehicles is growing and notably Tesla having its own nationwide charging grid, there is still much work to be done in order to make finding a charging station as easy as finding a gas station. Some ideas have come up are the possibility of wireless charging for vehicles. This idea provides the possibility of seamlessly charging vehicles if they drove down the highway or as they sat parked. This would simultaneously tackle the issue of range and charging speed since a vehicle could charge as it headed towards its destination [9]. The technology does show some positive results with some experimental data showing up to 95% efficiency for static wireless charging and 90% efficiency for dynamic wireless charging [10]. The technology still poses great difficulty to install, with charging coils needing to be installed into existing road infrastructure which could turn out to be costly.

Effect on Electric Grid[edit | edit source]

Increased number of electric vehicles charging on the electric grid could cause stress to the grid. Likely solution to this problem could be encouraging charging during load valley intervals on the grid. Load valleys filling is a form of load management that increases off-peak loads in order to utilize the surplus capacity. This could be initiated by a signal from the utility company to fill electric load valleys and avoid overloading the electric grid during peak hours[11]. Charging schedules at charging stations, when optimal, can increase revenues by up to 132% and reduce costs by 17.4%. However, these are less likely to be used in reality and instead real life situations would likely resemble a dynamic system. In the dynamic system the charging schedule would be set as soon as the electric vehicle plugs into the grid. A dynamic charging schedule that updates the charging rate as every electric vehicle plugs/unplugs from the grid was shown to perform better in terms of profit and cost than a dynamic schedule that did not update; with the changing dynamic charging schedule showing similar benefits to the optimal static charging schedule[12].

Alternative: Hydrogen Fuel Cells[edit | edit source]

Hydrogen fuel cell vehicles have been under development since the General Motors Electrovan unveiling in 1966. Hydrogen Fuel Cell Vehicles are becoming a growing alternative to electric vehicles but are limited to regions where the refueling infrastructure exists. Hydrogen Fuel Cell Vehicles also have the advantage of fueling up within 3-5 mins and a range of approximately 278 – 360 miles which matches expectations developed from consumers' use of gasoline. Study shows that users have been accepting of the technology and would be willing to switch to the technology provided the supporting infrastructure was available [13].

References[edit | edit source]

  1. https://www.energy.gov/energysaver/articles/new-plug-electric-vehicle-sales-united-states-nearly-doubled-2020-2021
  2. https://www.reuters.com/business/autos-transportation/biden-announce-approval-900-million-us-ev-charging-funding-2022-09-14/
  3. Zhang, Q. et. al., Factors Influening the Economics of Public Charging Infrastructures for EV-A Review, Renewable and Sustainable Energy Reviews 94, p.500-509 (2018)
  4. Wirges J, Linder S, Kessler A. Modelling the development of a regional charging infrastructure for electric vehicles in time and space. Eur J Transp Infrastruct Res 2012;12:391–416
  5. Schroeder A, Traber T. The economics of fast charging infrastructure for electric vehicles. Energy Policy 2012;43:136–44.
  6. a b https://electrek.co/2021/10/22/electric-vehicle-ev-charging-standards-and-how-they-differ/#h-electric-vehicle-charging-standards-for-connectors
  7. https://electrek.co/guides/tesla-supercharger/
  8. https://www.whitehouse.gov/briefing-room/statements-releases/2022/06/09/fact-sheet-biden-harris-administration-proposes-new-standards-for-national-electric-vehicle-charging-network/
  9. Norway's Wireless Charging Roads. 2021. [video] YouTube: Tech Vision
  10. Panchal, C., Stegen, S. and Lu, J., 2018. Review of static and dynamic wireless electric vehicle charging system. Engineering Science and Technology, an International Journal, 21(5), pp.922-937.
  11. L. Gan, U. Topcu and S. H. Low, "Optimal decentralized protocol for electric vehicle charging," in IEEE Transactions on Power Systems, vol. 28, no. 2, pp. 940-951, May 2013, doi: 10.1109/TPWRS.2012.2210288
  12. Jin, C., Tang, J. and Ghosh, P., 2013. Optimizing Electric Vehicle Charging: A Customer's Perspective. IEEE Transactions on Vehicular Technology, 62(7), pp.2919-2927.
  13. Lipman, T.E., Elke, M. and Lidicker, J. (2018) “Hydrogen fuel cell electric vehicle performance and user-response assessment: Results of an extended driver study,” International Journal of Hydrogen Energy, 43(27), pp. 12442–12454. Available at: https://doi.org/10.1016/j.ijhydene.2018.04.172.