That is so cool. I must admit I had never heard of the wonder bag so I had to look that up. It is amazing how much electricity you can use and not even be aware you're a hog. This little device is awesome.
When we lived in the barn and had no electricity, we had 4 solar panels. We were conserving at every corner. I learned quickly that the coffee pot or hair dryer would drain every ounce of saved power on the battery. A quick learning experience . We have solar at our house now and I love watching the output. Yesterday with the sun and the glare from the snow we put out more power than ever. During our first Spring and Summer we had no electric bill. That was nice! Great job on your canning and the yogurt. I haven't canned any meat yet. I feel like you do when I open a jar of tomatoes. I get nervous too eating my first canned foods from last year :)