Batteries vs EV? Is solar-based vehicle-to-home power feasible / coming soon?

We are planning a large solar (20 kw) array for a new home we are building and have several bids from installers.

Where I am getting hung up is on the battery side of things. All the companies we talked to want to sell us 3 or more PowerWall units. However, it seems like I could probably buy an EV with equal or more battery capacity for a comparable or lower price. Is the technology here or coming soon to utilize an EV battery as a backup electrical storage system instead of powerwall batteries? I keep hearing about “bidirectional charging” but our GC / electrician aren’t too familiar with the latest technology here, and the solar companies seem to just want to sell us batteries.

​

A few more details

* our power company has differentiated rates for pull vs pushed kwh and takes readings at short intervals (hourly?) not just monthly, so there is value in behind-the-meter storage

* outages in our area are rare and typically short so backup power is not critical

* this would be an infrequently driven 2nd car and we work from home so car would be parked in garage 95%+ of the time

​

appreciate any insights here, thanks