Expectations and Performance of Ubiquitous Electric Vehicle Charging Alternatives

Ubiquitous electric vehicle (EV) charging infrastructure seeks to expand access via basic single-phase ac receptacles, augmented with metering and simple control. This work links passenger EV energy needs from public survey data to assess whether basic infrastructure is realistic. Analysis of available data shows that 90% of daily energy needs of electric passenger cars can be sourced from basic receptacles. A low-cost EV metering unit is presented. Field tests of EV metering provide real-world user data on performance in terms of daily energy needs and confirm the general expectations. The approach supports substantial EV infrastructure expansion linked to home and work charging with modest grid impact. Results validate the expectation that at least 90% of daily driving energy needs can be supported with basic receptacles, and that business model considerations and flexibility issues can be addressed. Grid impact of slow charging is modest, with analysis suggesting 3% voltage drops in typical distribution feeders, but this could be an overestimate given continued slow reduction in residential electricity consumption. Battery stress is low with slow charging, implying long life and low energy losses. Ubiquitous access has the potential to support about 49% of all transportation energy needs, and appears to be the most cost-effective approach for massive scale-up of charging infrastructure.