Image is a graph from the electric company showing my usage for a day this week. From 6:30 AM to 8:30 PM we used absolutely no utility power.
I'm almost at the three week mark for having this system up and running. The first two weeks I only had 3 KW of PV input but I added another 5 panels to bring it up to 4 KW last week. It's also still running from a transfer switch in "off grid" mode because I don't yet have the prep work done to move my breaker box and start moving circuits to it. (That means I'm either on full solar+battery or utility, no mixing or load sharing).
Once I get it wired in fully, I'm probably going to switch to time-of-use billing. Unfortunately, I can't do that ahead of time because rather than just making off-peak use cheaper, it makes peak usage (M-F 7am to 9pm) extremely expensive while off peak dirt cheap. I wish there was a middle option, but it is what it is.
I'm also being very conservative with my battery usage since I want to have at least 50% in "reserve" to cover power outages. That's especially important during these heat waves. We could easily run 24/7 but would have to take a day off every so often to just let it charge back up since my system is a bit too small to cover all our usage indefinitely (at least if we want to run the A/C for comfort, that is).
Already checked, and we only have to involve the power company if any of the following:
As is, this system doesn't touch the grid at all since it's using a "break-before-make" transfer switch from an old Generac system - it completely disconnects the utility input before connecting the generator/PV's output into the home wiring. I'm also fine once I have it fully installed because it cannot feed power out of the utility input connection, so it remains isolated (unless I would just happen to hook it up backwards which would be a whole other set of problems lol).
Good to know you checked! Excellent job!