This is a feature that Sense Energy Monitor was made for, sadly it won’t be the first to market with it
If I am charging my car during the day and a cloud goes in front of the sun, or my hot tub heater comes on, it makes sense that I should be able to have the Sense turn off the car charging, I plug the charger into a TP-Link that Sense already knows how to control. Once there is more production than consumption (the exact thing the Sense is made for) it should trigger the car to start charging again, or perhaps the dishwasher to run.
I do make more solar than I need, but if I don’t use it, it goes out to the grid where I am only paid 1/4 what I have to pay for power. No Net Metering here anymore.
My current solution is less exact, I plug the car in when I take the dog for a morning walk, and unplug it when we take him to the park in the evenings.