I have been thinking for a while about how a surplus energy control system could work.
I have tried a few things and have built a test circuit, which also works so far. You can see the scheme in the graphic.
The function is as follows:
Turns on the relay 1 every 5 minutes for 0,5 seconds and measures the maximum available power with a test load (heater) at power meter 2.
When the battery is 90% charged + power meter 2 minus power meter 1 exceeds a certain value, relay 2 turns on an extra load. (in the Arduino the switching conditions can be easily adjusted as desired, this is just a simple example).
Do you have any suggestions for improvement?
I have not managed to send values from the Arduino to the Venus GX and display them in the portal. How can I solve this?