> Better yet it should be a software update for every existing electric car, even those without bidirectional hardware. Completely agree with everything you wr

> Better yet it should be a software update for every existing electric car, even those without bidirectional hardware. Completely agree with everything you wrote, but also: It doesn't even require participation of the car! Plain old J1772 already provides the EVSE real-time-ish control over the charge rate. Some charging stations already exploit this to split power between two ports. When one car is plugged in it gets full current. Upon detecting a second vehicle, the EVSE signals the first to reduce current draw (and it must comply). In other words, every EV can be grid-interactive with just a software upgrade to the EVSE, or, failing that, replacement of the (much cheaper) EVSE.