Excess Solar Power Charging



When a house’s solar array is generating more power than the house consumes, have the car use the excess energy to charge the batteries. This means the charge rate will vary depending on how much excess energy is being created. The timer would still be used to ‘top’ off the power in non-peak hours.


This feature is useful in regions where the electric company either provides no compensation for excess power generation or more commonly, a far lower rate of compensation than rates charging in non-peak hours (i.e. midnight to 6 am).

This system would have some outside costs – as the solar and main house power must be monitored, and a means (likely WiFi) to communicate with the car. Retail products that perform similar actions typically cost under $500. The car itself would require some additional software, but no hardware changes.



(voting combined from a close duplicate that has been removed)

Category: CY3XS Applies to:
     Created 21-Jan-2015


No additional hardware for this should be required. The data exists. Just needs to be fetched then used to set the charge speed
    Created 25-Jan-2020
Monitoring the voltage might be enough is a lot of cases. With the 230V system here while charging I see it rising to 236V when the sun shines brightly ... and dropping to 225 at night.

Reducing the charge amps when the voltage drops and increasing when it gets above the average again seems an easy algorithm to implement.
    Created 2-Nov-2019
Zappi looks to be a good solution for Europe. They only offer Type 1 and Type 2 connectors so far.  For those that want more information: https://myenergi.uk/product/zappi-product/
    Created 31-Jan-2019
The hardware already exists to do this called Zappi.

Zappi is a mode 3 charging station  ... If you have solar panels, or a wind turbine micro generation system, together with a Tesla then you could consider Zappi as a charging solution that does this functionality
    Created 31-Jan-2019
Controller of my solar panels has an API for this. But you might as well use that API to control (enable/disbale) the power to the charging cable.
    Created 26-Jun-2018
In the UK you are paid for all the electricity you generate, all of which it is assumed will go to the grid. If you use the electricity you have generated yourself it is effectively FREE - so there are big savings to be had by sucking off amps throughout the daylight hours. I set my charging amperage to 5 amps to benefit from most of the solar panel output!
    Created 10-May-2017
Solar charging needs information from the electricity meter or from current transformers to regulate the charging to use the solar surplus power that would otherwise be fed into the grid. The same mechanism should also enable Smart charging to ensure the total household consumption stays below the main fuse limit. Both Solar- and Smart Charging must also cater for three phase installations such as in Europe.
    Created 1-May-2017
alternative that the charging station change how much the car are allowed to use

then all cars at that location will use the correct level
    Created 30-Apr-2017