Electric Vehicle Energy Model#
The Electric Vehicle (EV) energy model in POLARIS captures the end-to-end energy lifecycle of battery-electric vehicles across all agent classes — personal vehicles, shared-mobility (TNC/SAV) fleets, and freight trucks. The model integrates three interconnected components:
Battery discharge: Link-level energy consumption computed as vehicles traverse the network, sensitive to vehicle class, speed, and travel/stop time.
EV charging stations: Spatially distributed charging infrastructure that manages plug availability, queuing, charging rates, pricing, and vehicle servicing.
Electricity providers: Time-of-use and fixed-rate electricity pricing that governs the cost of charging at each station.
Together, these components enable POLARIS to evaluate the impacts of fleet electrification, charging infrastructure placement, electricity pricing strategies, and range anxiety on traveler behavior and network performance.
The figure below provides a high-level overview of how the three EV energy components interact with the traffic simulation, routing, and shared mobility modules.
Integration with Other Modules#
The EV energy model interacts with several other POLARIS components:
Traffic flow simulation: Travel time and speed on each link feed into the discharge model.
Routing: Vehicles with low SoC may reroute to reach a charging station.
Shared mobility (TNC): Fleet operators use charging strategies (see Charging Strategy and Day-Ahead Charging) to schedule vehicle charging.
Freight: Electrified freight fleets use the same charging infrastructure (see Freight EVCS Optimization).
Demand model: Charging cost and range anxiety may influence mode and vehicle technology choices.