Impact of Building Loads on Cost Optimization Strategy for a Plug-in Electric Vehicle Operation

Abstract

Sustainable transportation growth will require wide adoption of electric vehicles in the near future. While the Plug-in Electric Vehicle (PEV) usually shares the same meter in a building, the overall energy cost typically increases due to absence of any optimal strategy. Smart EV charging strategies can help to reduce the energy cost. The amount of cost reduction largely depends on the integrated building load. This paper presents the impact of small and large building loads on an EV charging strategy for different Time of Use (TOU) energy rates of two different utilities. Both grid to vehicle (G2V) and vehicle to grid (V2G) operations have been studied with the goal to reduce the energy cost for a small building with less fluctuating loads and a large building with high fluctuating loads. Real time building loads of two buildings at the University of California Riverside and Nissan Leaf E-Plus EVs actual charging profile have been used in this simulation. Both operations have been examined with two different utilities' energy rates. Bidirectional operation always gives better results in comparison to the unidirectional operation in terms of cost. Large variation in electrical energy rate schedules results in higher percentages of savings for bidirectional operation regardless of the types of building loads.