Plug-In Electric Vehicles - Distribution system impacts and high level screening methodologies for calculating costs and benefits

Plug-In Electric Vehicles (PEVs) present an interesting dilemma for utilities - on one hand charging of EVs can result in overloading of distribution transformers requiring expensive upgrades, on the other increased electricity sales can increase a utility´s revenue; knowledge of both is essential in successfully integrating PEVs with the distribution system. In this paper we present a high-level screening methodology for identifying the reliability impact of PEVs on the distribution system; developing estimates of the distribution system upgrade costs; and calculating revenue potential of PEVs, and demonstrate its application on a prototype test feeder with characteristics typical of suburban and rural 12.47 kV feeders found on the west coast (including Northern California) of the US. The methodology presented here can assist utility executives and policy makers in short listing the most suitable policy alternatives/rate structures for a detailed cost/benefit analysis. The policies/rate structures so developed can encourage the adoption of PEVs while minimizing their adverse impact on the electric grid.