An empirical assessment of the feasibility of battery electric vehicles for day-to-day driving

Abstract

Driven by sustainability objectives, Australia like many nations in the developed world, is considering the option of battery electric vehicles (BEVs) as an alternative to conventional internal combustion engine vehicles (ICEVs). In addition to issues of capital and running costs, crucial questions remain over the specifications of such vehicles, particularly the required driving range, recharge time, re-charging infrastructure, performance, and other attributes that will be of importance to consumers. With this in mind, this paper assesses (hypothetically) the extent to which current car travel needs could be met by BEVs for a sample of motorists in Sydney assuming a home-based charging set-up, which is likely to be the primary option for early adopters of the technology. The approach uses five weeks of driving data recorded by GPS technology and builds up home-home tours to assess the distances between (in effect) charging possibilities. An energy consumption model based on characteristics of the vehicle, and the speeds recorded by the GPS is adapted to determine the charge used, while a battery recharge model is used to determine charging times based on the current battery level. Among the most pertinent findings are that over the five weeks, i) BEVs with a range as low as 60km and a simple home-charge set-up would be able to accommodate well over 90% of day-to-day driving, ii) however the incidence of running out of charge increases markedly for vehicles below 24 kWh (170 km range), iii) recharge time in itself has little impact on the feasibility of BEVs because vehicles spend the majority of their time parked and iv) while unsuitable for long, high-speed journeys without some external re-charging options, BEVs appear particularly suited for the majority of day-to-day city driving where average journey speeds of 34 km/h are close to optimal in terms of maximising vehicle range.