I think a couple of you are misunderstanding my efficiency question. It's not about comparing 12v to 120v loads. It's about the inefficiency of the inverter itself. The inverter uses some of the power coming from the batteries just to run the inverter. If you're running 12v loads, you're not wasting the power the inverter itself uses. I think our 300w pure sine inverter draws about 3amps all by itself independent of what it's outputting.
Also starting to look at hydro as an option as we're right on a river. Need to do more math as the initial purchase is higher than solar, but running 24/7 the power over time may end up costing less.