Ford Lightning has it, or its in the works. But expensive to have it installed such that its completely automatic. But the Lighning also has an option, quite affordable to go from 2400w 120v output, to 9800w 240v out. Now, its not automated. But at my family's farm, we already had a generator hook up (with proper switch to make it completely safe for utility etc). So when my Lighning arrives, and there is a power outage, we can just drive over to where the generator used to be, plug it in and throw the switch. Boom 120 kwh of backup power! (assuming one thought to charge up the truck when the forecast started to look bad!)
For more modest needs, there is also a well documented solution that many Leaf owners tried successfully. I bought a decent True Sine Wave inverter 1500w, and rigged the cables to my Nissan Leaf 12v battery. The Leaf charges the 12v battery using a DC-DC inverter that can handle about 1000w of load on the 12v side. Big lithium bats are at 340v I think. Anyhow, my little inverter will power my refigerator, wifi router, modem, and a couple lights for several days off my 40 kwh Leaf battery. Ain't pretty, but it does work. You leave the car in "ready" mode, otherwise, the 12v battery is dead in minutes.