As usual, I can't help with your question but you made me think of another. We never attempted a fully independent passive energy system as we always used more energy than we could ever maintain without the generator running for at least an hour a day. (we used about 225 amps a day). Another issue is that you can't heat water for showers without an engine and a cold shower isn't fun.

But the water jug issue is something else. I know that on a front loading refrig it helps because the cold air falls out and the air needs to be re-cooled but in a top loader it doesn't. If you add a jug of water at 80 degrees it has to cool it requiring quite a bit of energy to cool down. I did think of filling the empty area with blocks of foam.

Don't wish to deviate from Ron's question but anyone have a thought on the water or foam block issue to keep energy use lower?