DER VET User Guide/Technologies/Electric Vehicle

There are two distinct electric vehicle models in DER-VET. One is for a single (or small number of) electric vehicles that charge according to a rigid schedule with well-known charging requirements, as is the case with a single EV used for commuting charging at home. The other model is for a fleet, charging plaza, etc., where a large number of EVs are being charged intermittently. In this case, DER-VET does not model each vehicle individually, but instead considers the "controllability" of a time series charging load profile when shifting charging load.

DER-VET only models managed charging applications for electric vehicles - no vehicle to grid (v2g) or building backup using EVs (v2b) applications are considered. DER-VET will choose the optimal times to charge vehicles (either the single vehicle or fleet option) within the constraints provided to minimize the energy and demand charge costs of the site in concert with any other DERs.

Inputs

Single EV

Single EVs are modeled as a highly-certain and controllable load. The only requirement is that the vehicle(s) recharge some user-input amount before some user-input time every day (every day is the same). They are modeled as 100% controllable where the optimization determines the best times to allocate power to the EV chargers to minimize energy and/or demand charges. No reliability or market services are allowed. The user will input a kWh of charging energy requirement every day and the hours when the vehicle is home available for charging.

Minimum Charging Power

Tag	Key	Description
ElectricVehicle1	ch_min_rated	What is the minimum charging power the vehicle/charger can be throttled down to in AC kW?

Charging Power Rating

Tag	Key	Description
ElectricVehicle1	ch_max_rated	What is the maximum charging power the vehicle/charger can achieve in AC kW?

Charging Session Energy

Tag	Key	Description
ElectricVehicle1	ene_target	How much energy will the vehicle need to charge in each daily charging session?

Plugin Time

Tag	Key	Description
ElectricVehicle1	plugin_time	What is the first hour of the day when the vehicle is plugged in and available for charging (1-24)?

Plugout Time

Tag	Key	Description
ElectricVehicle1	plugout_time	What is the last hour of the day when the vehicle is plugged in and available for charging (1-24)?

Fleet EV

Workplace/campus charging is very similar to single EV charging but with fractional controllability. This case takes an time series aggregate EV load profile as an input along with a fraction of the load which is controllable. This will enable some fraction of the kWh in the aggregate EV load signal to be shifted around within as day for economic benefit.

Controllability

Tag	Key	Description
ElectricVehicle1	max_load_ctrl	What fraction of the energy used to charge vehicles in any given day can be shifted (0-1)?

Cost of Lost Charging Load

Tag	Key	Description
ElectricVehicle1	lost_load_cost	What cost should the model assume is associated with not meeting charging load in a day in $/kWh?