Uh, no. My battery was nowhere near $40k. Solar + battery + installation costs wasnt even that high, and thats before the 30% rebate from the federal government. Your numbers are way, way, way off.

I am not going to lie, most of what you said makes absolutely no sense to me. Basically what happens is my solar powers my house. Any additional power that is generated goes to my batteries. If my batteries are full, excess power goes to the grid, and I get a credit that I can use later. When the sun goes down, I start drawing from my batteries. If/when my batteries hit a threshold that I set from an app on my phone (I currently have it set to 50%), my house stops using power from the batteries and pulls from the grid. In the case of a power failure, I still have 50% of my battery left to protect me from power outages, which is enough to power my house at night at regular usage for hours.

Yes, I mostly have the batteries for power failures, but 90% of our power failures are less than 20 minutes, so I don't need it to last hours. When we do have extended outages, I just turn up my thermostat, and it will last hours.