Electric Vehicle Charging and Rural Distribution Systems

Rural electric distribution systems, compared to their suburban and urban counterparts, are characterized by longer, radial feeders with fewer consumers per mile. These feeders are limited in length more by voltage drop than thermal capacity. Corrective action must be taken when peak demand results in insufficient end-of-line voltage. Today, most energy consumed by the transportation sector is delivered via fossil fuels. Electrification of the transportation sector has the potential to increase peak demand on feeders that have historically seen little to no load growth. Likewise, additional energy sales without a corresponding peak demand increase are possible. Since it is the utility's responsibility to ensure adequate voltage is provided to each consumer, and most economical to deliver additional energy via existing capacity, both "on-peak" and "off-peak" charging of electric vehicles require consideration. An electrical model of Ohio rural electric system is combined with estimates of future electric vehicle adoption and existing transportation data. Residential energy consumption collected hourly via the owner's Advanced Metering Infrastructure (AMI) is modified to represent on-peak electric vehicle charging. The existing system load profile and load factor are reviewed, and off-peak Time-of-Use periods identified.