Introduction
Tariffs are used to provide a price for sessions and charge detail records. The table below outlines the configurable information for a tariff.
| Field | Description | Roaming |
|---|---|---|
| Ocpi identifier | This code is used when the tariff is shared with roaming partners via the OCPI protocol. See the OCPI paragraph for more information. | ✓ |
| Hubject identifier | Identifier that is used when creating a so called "service offer" on the Hubject roaming platform. See the Hubject paragraph for more information. | ✓ |
| Start tariff | The price when a session is started. | |
| Price per Kwh | Price per kilowatt-hour for the session. Prices are rounded per watt-hour. | |
| Currency | The currency used for the session. | |
| VAT | The applicable VAT for the sessions. | |
| Charging Time | Price per minute as long as energy is being transmitted. | |
| Parking Time | Price per minute when the EV is connected but no energy is transmitted. |
Hubject
| Attention: It's mandatory to have a tariff available for Hubject roaming sessions. If no tariff is selected on a charger, default values for AC1, AC3, and DC will be used based on the power of the EVSE in the Location overview screen. |
When tariffs are used for a Hubject roaming session, the tariff codes need to match the "name" of the authorization service offer in the Hubject portal. To simplify this process, it is possible to change the Hubject identifier of a tariff. Note that only one unique Hubject identifier can be active.
OCPI
For roaming communcation via OCPI (like e-clearing, Gireve or P2P connections with EMPs), we support the tariffs module. This means that tariffs are exchanged with the OCPI roaming partners. The EMP will exactly know what the CPO price will be for a certain EVSE.
Active tariff
When a session starts, the applicable tariff is determined based on the session's start datetime . This tariff will be used for the entire session. Changes to the tariff during an ongoing session will not be applied.
Calculation
The total amount of the session and CDR is calculated using the following formula, where MeterStart and MeterStop are transmitted in Wh.
| Total = Tariff.StartTariff + ((StartTransaction.MeterStop - StopTransaction.MeterStart) * (Tariff.PricePerKwh / 1000)) When charging time and/or parking time tariff is configured: Total ChargingTime = RoundUp((Duration - GracePeriod) / StepSize) * Tariff. |
Time-based tariffs
When a time-based tariff is configured, it will be added to the startariff and the energy tariff. This enables to use Parking Time to discourage EV drivers to keep their car on the parking spot while not charging. Make sure that these price components are clear for the EV drivers to avoid confusion. All tariff components including the time-based tariffs are also shared via OCPI. The session screen also shows in detail how the total price is being calculated.
Grace period
Setting up time-based tariffs allows for configuring a grace period, providing leniency to EV drivers. This allows them time to remove the car before getting charged for parking without charging.
Smart Charging (AC/DC)
We advise using time-based charging only on DC chargers. Smart charging on an AC charger can suspend a charging session, making time-based charging unfair to the EV driver. Parking time will also be reset to 0 if a short amount of energy is transmitted at the end of a charging session.