In many cases, your solar production will be different from the charge power of your car. Since we are not able to modulate the charge power of your car (yet), tado° Smart Charging App will calculate the share of power that has to be drawn from the grid to charge your EV. From this, tado° will calculate the average price per kWh to charge your EV. The calculated price is taken into account in the optimization.
Only for those moments where the calculated price is lower than (for example) the off-peak rate at night, the algorithm will charge your car.
We are not able to modulate the charge power (yet) that is delivered to your car. Therefore, we can not charge your EV with the precise amount of energy that your solar panels produce.