This paper examines a method to model plug-in electric vehicles as part of the power system and presents results for the contribution of plug-in electric vehicles to balance the fluctuating electricity generation of renewable energy sources.The scientific contribution includes:A novel approach to characterizing fl uctuating generation. This allows the detailed comparison of results from energy analysis and is the basis to describe the eff ect of electricity from renewable energy sources and plug-in electric vehicles on the power system.The characterization of mobile storage, which includes the description of mobility behavior using probabilities and battery discharging costs.The introduction of an agent-based simulation approach, coupling energy markets and distributed grids using a price-based mechanism design.The description of an agent with specific driving behavior, battery discharging costs and optimization algorithm suitable for real plug-in vehicles andsimulation modelsA case study for a 2030 scenario describing the contribution of plug-inelectric vehicles to balance generation from renewable energy sources inCalifornia and Germany.