Add EV Batteries
1. The three charging strategies of EV batteries
Electrical Vehicle (EV) Batteries can be added in your scenario as storage technologies with fixed size. 3 charging strategies can be modelled.
The target state of charge (SoC) at the end of the charging cycle is the amount of energy that will have to cover the driving distance (as defined by the user) during the day.
Charging strategy  Charging  Discharging (to grid) 

Dump (Monodirectional)  Vehicle battery charges at the plugin hour. The charging power is constant and equal to EVPlugin Power (kW) until the vehicle battery is fully charged.  Not allowed 
Smart (Smart  Monodirectional)  Vehicle battery charges at the (optimal) best hour after plugin. The maximum charging power is EVPlugin Power (kW).  Not allowed 
V2G (Smart  Bidirectional)  Vehicle battery charges at the (optimal) best hour after plugin. The maximum charging power is EVPlugin Power (kW).  Vehicle battery can discharge stored electrical energy to the grid during the hours of plugin. The maximum discharge power is EVPlugin Power (kW). 
Monodirectional (Dump)
Smart Monodirectional (Smart)
Smart Bidirectional (V2G).
2. How to add EVs as storage technologies
On the Supply Technology page, Storage Technology Candidate section, click on Create Custom → toggle on Emobility Parameters and fill in the necessary entries.
In the “Storage Parameters” section, the user can leave the Technology Capacity and Maximum Capacity as default as this will be overwritten by the EV Battery Size in the “EMobility Parameters” section.
The user also does not need to fill the Dis/Charging Parameters section as this will be overwritten by EV Plugin Power in the “EMobility Parameters” section.
3. Definition of parameters in Sympheny
The rest of the parameters needed for the definition of the EV batteries are explained in the table below:
PARAMETER  UNITS  EXPLANATION 
EMOBILITY PARAMETERS 


EV Plugin Time  hour  The hour of the day when the EV batteries can be pluggedin to the electrical circuit of the system. It can’t be “00:00” 
EV Plugout Time  hour  The hour of the day when the EV batteries can be pluggedout to the electrical circuit of the system. It can’t be “00:00” 
EV Plugin Duration  hours  The total hours that the EV battery will be connected. It must be less than 24 hours 
EV Battery Size (kWh)  kWh  The total size of the EV batteries in kWh considered in the system 
EV Plugin Power (kW)  kW  The maximum possible power in kW to charge the EV batteries. For Dump charging, this is the constant power that the battery charges at until it is charged to the final SoC. 
EV SoC start (%)  % of total capacity  The initial State of Charge (SoC) of the EV batteries when they are pluggedin. 
Maximum SoC (%)  % of total capacity  The maximum State of Charge (SoC) allowed for the EV batteries 
Driving Distance per day (kms)  km  The driving distance (kms) of the EV which must be able to cover after charging the EV battery. Used for calculating the final SoC of the battery at the end of the charging cycle. 
EV Average kWh per km  kWh/km  The average consumption of the EV in kWh per km driven Used for calculating the final SoC of the battery at the end of the charging cycle. 
While running the scenario some warning messages might be sent to alert about the following:
That the charging power during the entire charging cycle won’t be enough to reach the target Driving Distance for the car.
That the EV battery has enough starting SoC to cover the target Driving Distance of the car, so the charging won’t be necessary. (Only for the cases of Monodirectional charging strategy)
In this case, you will simply have to adapt the input parameters according to the alert sent.
4. Can I model EV as a demand instead?
In Sympheny, you can model EV as a demand as well. To do so, you can add a typical electricity demand profile as detailed under section Add Energy Demand. By defining an exogenous profile, you will not capture the dynamic charging and discharging behaviour of smart charging.
As storage technology  As demand  

Total electricity consumption by EV  The daily electricity consumption is the amount of energy required to reach the SoC level at end of the charging cycle, plus standby losses.  As described by hourly demand profile 
Charging strategy  Dump, Smart  monodirectional, Smart  V2G  As proxied by the exogenouslydefined profile Load shifting can be considered by adding a ‘virtual’ battery (whose sizing has to be decided by the user) 
Optimisation of EV versus gasoline fleet  Not possible, as EV demand has to be defined  Possible, with a vehicle energy demand pattern that can be fulfilled by either electricity or gasoline fuel. 
Typical case for usage 


Questions answered with model? 
 


5. An example of EV modelled
The outputs below are of a Dump EV with the following parameters:
EV Battery size  37 500 kWh
EV SoC Start  10%
Plugin time  08:00
EV plugin duration  8 hours
EV plugin power  30 kW
distance travelled per day  26'250 km
EV average kWh per km  0.24 kWh/km
From the results below,
The SoC at 8 am (plugin time) is 3'750 kWh (10% of the batterie size, 37'500 kWh).
The target SoC is 37 500 kWh
The EV charges at max plugin power at 30 kW in the first hour, and 4.09 kW in the subsequent hour to reach the target SoC.
There is continuous charging during the plugin cycle to recharge the power loss from to standby.