Step 11: That's it!
A independent 12v solar system won't take most normal houses off the grid entirely.
My computers, TV, entertainment center, fridge, chest freezer, and kitchen appliances all still rely on the utility company.
The 176 watt-hours of 12v I use each day is much less than the 7400 watt-hours of 120v AC I use each day on average.
However, by moving just a few things to solar, the effect is tangible, and it adds up to more than it seems like it would.
One reason for that is because most things that can run on 12v operate more efficiently when they run on it directly. Those power brick plugs waste a lot of energy converting 120v to 12v (you can tell by touching one when it has been plugged in a while - anything that is warm to the touch is wasting electricity in the form of heat). 12v lighting is also inherently more efficient, and using it allows me to use affordable LED lamps which use 1 watt each (a opposed to a 15watt florescent, or 60watt incandescent).
If I had everything in my solar system running on 120v AC it would use up to 400watt hours!
That's more than twice as much, to provide the exact same amount of end-use power. The majority of the difference would be waste heat - which in summer could end up costing me even more, as I run additional fans (or even AC) to cool the house down.
Another reason my tiny solar system helps disproportionately is because many utility companies have a progressive rate structure. The more you use, the higher the price per kilowatt-hour (KWh) (the opposite of a bulk discount). Dropping just a couple hundred KWh allowed me to stay entirely under the baseline, lowest rate.
I'm still working on ways to lower my electricity useage even further. I recently discovered my chest freezers compressor was staying on even when the temperature was below 0 degrees (F). I adjusted it to go no lower than 10 degrees. I also started charging my truck almost entirely with solar, which means less household AC being used by its onboard charger. I'll see how much that helps next month.
(update - after my last shopping trip, I realized the chest freezer was still only half full, so I moved some things around, and packed everything into the little freezer built-in above the fridge. The door just barely closed, but it meant I could unplug the chest freezer completely, which is one of my biggest remaining 120v grid draws)