Part of me wants to be like Nelson (Simpson's) and say 'Ha Ha!'

[btfc]

“ Maybe electric cars will be able to be used for battery backup at some point. “

Yes, the Ford Lightning is using this as a selling point:

https://www.ford.com/trucks/f150/f150-li...-lightning


Nissan Leafs are also suitable for this, and have been popular in Australia in off grid situations for several years as a result.


https://www.greencarreports.com/news/107...-it-to-u-s

https://www.greencarreports.com/news/112...in-the-u-s



I live off grid and have been looking into this for the last few years.