Electricity Provider#
Electricity providers in POLARIS define the cost structure for electricity delivered to EV charging stations. Each provider is an agent that can represent a utility company or an independent power producer, and supplies pricing information used by charging stations to compute per-session charging costs.
Pricing Models#
Each electricity provider supports the following pricing mechanisms:
Fixed-Rate Pricing#
A constant fee per kilowatt-hour applied uniformly across all hours of the day. This is the simplest pricing model and is used when time-of-use data is unavailable or when flat-rate tariffs are being evaluated.
Time-of-Use Pricing#
A schedule of pricing periods defined by:
End times: A vector of period endpoints (in simulation time units). Each period begins where the previous one ended.
Pricing type: The type of tariff applied during each period (e.g., peak, off-peak, shoulder).
Pricing value: The cost per kWh during each period.
At any point in the simulation, the provider determines the active pricing period and returns the applicable retail rate. This enables analysis of demand-response strategies, where fleet operators may time their charging to coincide with off-peak electricity rates.
Integration with Charging Stations#
Charging stations query their associated electricity provider to obtain the current retail rate. The per-session cost accumulated in the charging record combines the station’s plug-level unit price with the provider’s retail rate. This two-level pricing structure allows scenarios where station operators set markups above the wholesale electricity cost.
Scenario Applications#
The electricity provider model enables several policy-relevant analyses:
Time-of-use tariff impacts: Evaluating how peak/off-peak pricing shifts fleet charging behavior across the day.
Grid stress analysis: Identifying periods of high aggregate charging demand that coincide with grid peak loads.
Pricing sensitivity: Assessing how changes in electricity cost affect the total cost of ownership for EVs and the operational costs of electrified TNC and freight fleets.