Hi Johara,
there is an emission class "Energy", that models electric energy consumption of vehicle.
To employ this model for an electric vehicle, there exist two types of so-called vehicle devices in SUMO (to my knowledge). One of these devices needs to be assigned to the selected vehicle with properly defined physical parameters to get reasonable results.
The first one - battery device - is used by SUMO community
mostly
It is suitable for modeling electric vehicle with battery pack, that charges at charging stations.
The second one is a model for a hybrid trolleybus - elecHybrid device
It is suitable for a trolleybus going under overhead wires and using a smaller battery pack for moving without overhead wires.It is good to known, that elecHybrid device is implemented by me and my colleague at University of West Bohemia. We use it successfully for our internal project, but we are fully aware of some smaller obstacles that can come up for a novice with SUMO. However, if you find the elecHybrid device interesting for you, I am open to give you further information or answer some questions to this device.
Maybe someone will be capable to give you more understandable info. I hope, at least something above-mentioned can help you.
Best regards,
Jakub