Charging Station Class

Description: An electric vehicle charging station
Detail:

See also Charging Station Property Reference for a detailed list of properties for this class of object.

Overview

Charging Station can represent any type of charging infrastructure for electric Vehicles. This could be domestic or commercial on-premise charging, or a station in a charging network e.g. supercharger. Charging Station objects can represent multiple physical stations via the Units property. This allows you to expand the size of the charging infrastructure being modeled without having to create additional Charging Station objects i.e. it is the 'key' property.

Charging Stations connect to the electric grid with the Charging Station Node membership. Vehicles connect to the Charging Station with the Vehicle Charging Stations membership and the Share property i.e. vehicles move between charging stations according to this property and can be partially present at multiple charging stations simultaneously - a feature that is designed for modeling a large fleet of vehicles and charging stations with a probabilistic model for the present location of the fleet.

Properties of Charging Station allow you to select between three levels of complexity with respect to charging and discharging of electric vehicle batteries:

  • 'V0G': Charging demand from electric vehicles is 'fixed', based on distance travelled and efficiency, and that charging demand must be met as soon as the electric vehicles attach to the charging station.
  • 'V1G': Some or all of the charging demand can be deferred in time so that charging occurs at a more economic time.
  • 'V2G': The electric vehicle batteries can not only charge from the station, but also discharge to the grid.

Charging draws electric power from the grid. Charging Stations have a Max Charge Rates in kilowatts. The total available charge rate scales up and down with the number of Units. If Vehicles Charge Efficiency is less than 100% then some of this energy will be lost and this is reported in the Losses output property.

V1G is defined with the multi-band properties Deferrable Load and Deferment Period. The optimization will choose whether or not to defer the charging load according to the limits defined by these properties. The amount of load deferred is reported in the Deferred Load property.

V2G is enabled by setting the Max Discharge Rate in kilowatts. Discharge from batteries is subject to the Vehicles Discharge Efficiency and any losses are added into the Losses output property. Discharge appears as additional Generation in the electric grid, and the optimization will arbitrage the electric price to find the best times to charge and discharge.

All charging and discharging is subject to a use-of-system charge, which might, for example, represent distribution system costs.

Charging Station load and generation is reported at the Node, Region and Zone as Charging Station Load, Charging Station Deferred Load, and Charging Station Generation.

Charging Stations can provide ancillary services via the Charging Station Reserves membership. 'Raise' type services can be provided when:

  • The charging station defers some charging load; or
  • The charging station holds some discharge capacity in reserve.

'Lower' type services can be provided when:

  • The charging station holds some deferrable charging load in reserve; or
  • The charging station is discharging to the grid.

The co-optimization will trade off charging and discharging with electric and ancillary services prices to find the optimal combination. Charging Station output properties report the amount of each type of reserve provided and the revenue earned from reserve provision.

How to use Charging Station

Refer to the Vehicle page for details on how to model EVs and charging.

Charging Station Expansion

Charging Station supports expansion in LT Plan. The key input properties are Max Units Built and Build Cost and optionally FO&M Charge. Expansion costs can be treated as a lump sum or automatically annualized by defining WACC and Economic Life. Other available constraints related to expansion are:

Charging Station retirement occurs automatically after the Technical Life. Retirements can be optimized if you define Max Units Retired and will incur a Retirement Cost.