I'm considering moving from an E7 tariff to Go because we only use off peak energy anyway with the powerwall now installed. The powerwall runs the whole house for the rest of the day.
The Go tarrif would be half what we're currently paying with standing charge identical. Is this the no-brainer it looks like to me?
Our PW cannot last a whole day, certainly not at the weekend. We seem to consumer around 2KW before the E7 cut off starts, add on the base load for additional 3hrs it will means the PW would be empty by about 7pm especially on a weekend. 4hrs will also not fully charge a drained PW - it'll go over by 1hr or so only though.
Car usage only you will know. We tend to do long weekend road trips, often back to back, so need to charge from 10% to 90%, on E7 somethings thats not possible forget just 4hrs of charging!
All in all the cost savings/difference for us on E7 versus Go would be minimal, add in the hassle of switching to a smart meter, I see no incentive to switch.
If you can be sure all your electricity usage is within the 4hr GO period than the numbers will clearly work!