On the ease of being green: An investigation of the inconvenience of electric vehicle charging

Abstract

This paper presents a quantitative investigation of the inconvenience of electric vehicle (EV) charging relative to internal combustion engine vehicle (ICEV) fuelling in terms of the time penalty likely to be experienced by drivers. A heuristic approach to deriving idealised charging schedules from over 39,000 week-long travel diaries from the UK National Travel Survey is presented in order to quantify the expected convenience parity-the point at which EV charging and ICEV fuelling are of comparable conveniencefor combinations of battery capacity, charger power and access to charging at different locations (home, workplace and public destinations). It was found that although the majority-up to 95%-of individuals who can charge at home are expected to be able to reach convenience parity with battery sizes currently available in EV models at the 'affordable' end of the market, this is significantly less likely for those who rely on workplace or public chargingand particularly for those who must rely solely on en route charging. These individuals are expected to suffer considerable inconvenience associated with EV charging relative to ICEV fuelling, and although greater battery capacities and charger power ratings are expected to lessen this inconvenience, there remains a significant gap in the convenience of EV ownership between those who can charge while parked at home and those who cannot. Further analysis is carried out to long journeys that cannot be made on a single charge; 'range anxiety' being a major obstacle to widespread EV adoption. It was found that if drivers are compliant with the UK Highway Code in taking regular breaks on long journeys, fewer than 0.01% of trips are expected to be delayed by charging when using battery capacities of 40-60 kWh.

Electric vehicles: Battery capacity, charger power, access to charging and the impacts on distribution networks

“…The study found that this was especially true for EVs with larger batteries: those with capacities above 35 kWh chose to charge on average every 3.2 days, versus every 1.5 days for those with capacities under 25 kWh [51]. To address this important point, the work presented in this paper models drivers' likely charging schedules derived from week-long travel diaries, using a heuristic method originally presented in [52], in which the focus is to minimise the number of charging events (and the associated inconvenience) subject to meeting the energy requirements of a predefined set of journeys.…”

“…In this paper, a fleet of EVs is simulated within an electrical distribution network according to the spatial distribution of existing vehicles according to Census data. Each vehicle is assigned a week-long travel diary from the UK National Travel Survey (NTS) based on key demographic attributes of the driver found from Census data, and these travel diaries are used to derive charging schedules from the heuristic presented in [52] as already mentioned. By modelling the heterogeneity in travel habits amongst a population and the resulting demand from EV charging, it is suggested that this approach can contribute to a better understanding of the area and network-specific impacts of the electrification of private transport.…”

“…In this paper, a greedy heuristic algorithm originally presented in the author's earlier work [52] is used to derive 'idealised' charging schedules from NTS travel diaries (though a summary is provided in this section, the reader is referred to [52] for a detailed explanation of how the heuristic works). These idealised charging schedules represent a scenario in which EV charging is seen by drivers as an inconvenience, and therefore something that they would aim to minimise.…”

“…It is noted that the pricing of different charging types is not considered in this study, nor in the algorithm originally presented in [52]. This is expected to have a considerable effect on where people choose to charge, and is further discussed as piece of future work in section 8.…”

Evaluation of Three Different Approaches for Automated Time Delay Estimation for Distributed Sensor Systems of Electric Vehicles

“…Political guidelines in various countries to decarbonize individual mobility led to an exponential growth of Electric Vehicles (EVs) in offers and sales. However, one obstacle for the success of EVs is the so-called range anxiety [1]. Customers are afraid that an EV is not able to provide the range they need for all of their journeys.…”