E-Mobility
E-mobility refers to full electric or hybrid vehicles, powered by batteries or hydrogen fuel cells that convert hydrogen into electricity. Nowadays many countries set a goal to increase the number of electric vehicles, in order to integrate the environmental and economic strategies. E-mobility in turn aims to meet the emission requirements and market demand at affordable costs. The e-mobility market has a big growth potential and therefore it was included in Polysun. Polysun allows the user to add an e-mobility component in the PV system and calculate the self-consumption, among other things.
There are different options, how e-mobility projects can be created. The recommended solution for e-mobility though would be to start the project and choose an appropriate template from the list in the bottom left of the graphical user interface (main window).
There are currently three templates available:
56e: Space heating + domestic hot water + electric vehicle (PV + heat pump with a smart SG-Ready controller)
50s: Electric vehicle charged by photovoltaic energy
50t: Electric vehicle with programmable charge controller
50u: Electric vehicle (bidirectional) with programmable charge controller
The main difference is that the system diagram in the template 50s can be used for charging the battery of the electric vehicle only from the PV system. Template 50t can be used to charge the battery and other electric consumers from the photovoltaic field as well as from the electricity grid as a backup source. Energy supply is managed using the programmable charge controller with defined logic, which is described later in this chapter. Finally, template 50u allows discharging of the electric vehicle, as long as the state of charge is above 50 %. Template 56e is for the demonstration of sector‑coupled systems with intelligent controllers.
You can choose the most appropriate template by double-clicking on it. As soon as the template is chosen, it could be adjusted in accordance to the project requirements. The system includes a PV module field, inverter, electrical consumers, electricity grid and the e-mobility component which has not been added as an electric consumer, but as a battery. In the dialog window of the e-mobility component the following parameters can be set:
| Parameters | Description |
| Type | AC is an electric storage for stand-alone or hybrid PV-Systems |
| Electric vehicle | The most popular electric vehicles on the market can be chosen from catalog. It is also possible to add the self-defined vehicle. |
| Charging station | The appropriate charging station can be chosen from the catalog based on the nominal power and producer. It can be defined in the catalog, how long the battery will be loaded in order to optimize self-consumption. |
| Mobility profile | The mobility profile is defined on the hourly or weekly basis. The mobility profile can be opened by clicking on the “Mobility profile” or on the symbol “Edit profile”. In the matrix the user can define when the electric vehicle is driven and when it is at the charging station. The horizontal axis represents the hours of the day, the vertical axis the days of the week. The charging time shall be defined as well as the time on the road and kilometers driven with electric vehicle for every day during the week. Furthermore, it can be specified at which times the charging station allows discharging. |
| Performance ratio for battery charging | Is a user-defined relation between the instantaneous PV power and the total nominal power of all generator fields. The aim is to avoid to feed-in midday production peaks into the external grid. 0% means that the battery can be charged at any time; 100% means that the battery will never be charged. |
| Deep cycle threshold | Defines the cycle depth of a deep discharge. The value relates to the discharge range of the battery. 100% is the discharge of the battery up to the minimum battery capacity. |
If two or more electric vehicles are added, the programmable charge controller has to be set for each vehicle separately, especially when the charging profiles of the electric vehicles are different. The order for charging the vehicles will be the same as the e-mobility elements have been added to the system diagram.
Electricity from the PV system can be used for household electric consumers and/or for electric vehicles. If the e-mobility is the only electric consumer in the given system then the number of electricity profiles for the household has to be set to 0.
If the system includes domestic appliances as well as E-Mobility, the loading order is as follows:
1st priority: electric vehicle, if there is any demand
2nd priority: domestic appliances (electricity consumption profile)
3rd priority: battery
4th priority: the surplus of electricity is supplied to the electricity grid
The pre-defined order can be changed using a programmable charge controller.
In addition to the control mode and the controlled battery power, the electric vehicle offers a third controller output, “Status charging station”. By setting the charging station status to 1, it can be forced to allow discharging. When set to 0 (default), the e-mobility profile specifies whether discharging is allowed or not.
In the template 50t the charging logic is implemented in the programmable controller in the following way:
| Operational state | Conditions | |
| 1 | Electric vehicle is charged from PV | If the energy available from the PV system is more than 100 kWh AND Electric vehicle is under operating conditions AND Battery state of charge is more than 0.95 |
| 2 | Electric vehicle is charged from the grid | If the energy available from the PV system is less than 100 kWh AND Electric vehicle is under operating conditions AND Battery state of charge is less or equal 0.80 |
| 3 | End case | Is always true. This operational state is used to find the gaps in the defined logic if there are any. If none of the abovementioned conditions are true, then the operational condition “end case” is applied. |
Simulation and evaluation
The main simulation results are given in the component results, where the average monthly and annual values, as well as maximum and minimum values for each individual component are shown. Separate tabs are provided for each electric vehicle. The priority for the charging, when not defined otherwise, is given as follows: “E-Mobil 1” has the first priority, “E-Mobil 2” the second, and further in kind. The tab can be renamed by the user in the dialog window.
The component results show the monthly and yearly values of battery charge needed to drive the electric vehicle with the given profile (battery charge), the portion which was supplied from the photovoltaic system (battery charge PV) and the rest of the energy supplied from the electricity grid (battery charge grid). The detailed description for each row in the table can be found in tool-tips.
The different values can be displayed in the graphical evaluation. The graphic shows, which part of total energy demand (black) is covered by PV (green) and at what extent the backup energy from the grid is needed for the second vehicle in the given project.
The detailed simulation analysis shows instant energy available from the PV system as well as the state of charge of the battery in percentage and in kWh and the distance run in the certain time-step. The distance shown is not cumulative. The total distance per hour given in the mobility profile.
