Did not know where to put this but with PG&E power outages I would love to use my car as battery backup. I checked into the powerwall but my cost would be about $18,500 installed for a 27 KW system. The batteries are about $13,000 of the cost. Since my car has 85kw it would make more since to use it. I know Tesla does not supply a way to do it since the original roadster. However there is a company Occiaso (Ossiaco: Power will never be the same.) that is coming out with a system to do it. Has any on checked it out and wonder if PG&E would allow it.
Sounds interesting, wonder how hard it is to install cannot believe it could be a whole house backup.
Tesla changes the warranty when PowerWalls are charged from the grid - and not the sun. If Tesla supported using a vehicle battery for powering a house, it's likely that would change the vehicle's battery warranty. And if Tesla doesn't support vehicle use as a power source, doing so would likely invalidate Tesla's battery warranty. We have 4 PowerWalls, capable of providing up to 50KWh of power (in theory) - and an S 100D and X 100D, which could provide a lot more power... Though in an extended power outage (days), the large charge in the vehicles should allow us to run for days without having to recharge the vehicles and focus our solar/PW power on the house circuits.
V2H/G does sound like a great idea but as was noted, vehicle manufactures are not going to rush to this and also support a warranty on the battery. We are already seeing issues with restricting charging and numerous reports of larger than expected battery degradation just with normal driving on Teslas. I would suspect if anything we see Tesla be more proactive about the combination use of cars and Powerwalls by perhaps allowing the car to come home and top off a solar supported Powerwall when it's constantly cloudy out for days etc. In theory a well designed solar supported Powerall install could last forever if it did not cloud over and you always had solar. That will never happen so filling those "gap" days would be nice with V2H technology IMHO. OP: If your car is out of warranty (probably not since the battery on an 85 is covered for 8 years), you could go for this but I would seriously think Tesla would walk away from any claim you tried to make if you did this during your battery warranty period. I have no idea how this would work with a Tesla. Scanning the website it looked like they can max the power from a car at 7kW. This assumes that you can go bidirectional from a Tesla plug and at that rate. Powerwalls can do 5kW each. Many people have 2-3 Powerwalls and even then are restricted by the types of home devices they can support (for example I had to isolate my heat pumps and spa as they can draw 20 kWs total at times). So you would need to do the same serious home energy audit that you would for Powerwalls and really see how much kW (continuous) they can support to run your critical home loads. BTW there is a 26% tax credit for solar supplied Powerwalls so your $18,500 is about $13,700 if that helps.
