I'm about to get a P100D X and a model S after that so my house has been rewired with a 100a circuit for my two HPWCs. While doing that, I purposely upgraded all my breakers to tandems to leave space for a dual pole 40a breaker required for a future solar roof . Tesla does not release wiring diagrams for the powerwall which is weird but I assume the powerwall is connected to the backfeed circuit breaker (which in this case would be the 40a dual pole that currently unwired) and the solar roof is going to plug into the powerwall, is that correct? If the powerwall will need it's own backfeed circuit, I wont have space right now to plug in both a solar panel and the powerwall. Since I am spending that much money for the roof+powerwall, I want the entire house to be backed up in case there is a blackout. Now from what I understand, I need to fit the gate way between the utility meter and my main panel, which is impossible given my panel integrates a meter socket. What I am going to do is to get a stand alone meter socket right next to my main panel and have my power company move the utility meter to that new socket. That way the gateway can be installed right between the meter socket and my main panel. However, given that my panel currently only has 1 dual pole space left, any ideas on being able to fit both circuit breakers for the powerwall and solar roof lines in there? My current idea is to use that last free dual pole breaker to wire in a subpanel right next to my main, and from there wire in the new solar and powerwall breakers.I know the solar backfeed needs to be the farthest breaker away from the main, so that will be last. Do powerwalls connect to each other or do they each need an individual circuit breaker? What size breaker will they require? Any thoughts?